Stimulus Onset Asynchrony Research Articles

Effects of aging on event-related potentials to single-cycle binaural beats and diotic amplitude modulation of a tone

Aim of the study is to determine whether the auditory processing of temporal fine structure (TFS) is affected with normal aging, even in the presence of normal audiometric hearing and fine cognitive state; and, if it is, to see whether a comparable effect is also observed in the processing of a diotic change in sound envelope. The event-related potentials (ERPs) to binaural beats (BBs), which are the responses of the binaural mechanisms processing TFS of a sound, and the ERPs to diotic amplitude modulation (AM) stimuli, which are the responses of the monaural mechanisms processing the changes in its envelope, were recorded from thirteen young university students and ten senior but active university professors, all with normal hearing in low frequencies. To obtain directly the specific BB responses without confounding monaural frequency change-evoked responses, we used single-cycle BB stimuli with temporary sub-threshold frequency shifts. BBs of a 250-Hz tone and diotic AM of the same tone with similar perceptual salience were presented with 2-second stimulus onset asynchrony. The N1 components of the ERPs to both stimuli displayed notable age-dependent changes in their scalp topography and significant amplitude reduction and latency prolongation in the elderly. These amplitude and latency changes were at similar rates for the two stimulus types, implying that the auditory TFS and envelope processing mechanisms are proportionally affected by physiological aging. These results may serve as control data in future studies investigating the effect of aging-associated cognitive pathologies on auditory TFS processing.

Nonretinocentric localization of successively presented flashes during smooth pursuit eye movements.

Keeping track of objects in our environment across body and eye movements is essential for perceptual stability and localization of external objects. As of yet, it is largely unknown how this perceptual stability is achieved. A common behavioral approach to investigate potential neuronal mechanisms underlying spatial vision has been the presentation of one brief visual stimulus across eye movements. Here, we adopted this approach and aimed to determine the reference frame of the perceptual localization of two successively presented flashes during fixation and smooth pursuit eye movements (SPEMs). To this end, eccentric flashes with a stimulus onset asynchrony of zero or ± 200 ms had to be localized with respect to each other during fixation and SPEMs. The results were used to evaluate different models predicting the reference frame in which the spatial information is represented. First, we were able to reproduce the well-known effect of relative mislocalization during fixation. Second, smooth pursuit led to a characteristic relative mislocalization, different from that during fixation. A model assuming that relative localization takes place in a nonretinocentric reference frame described our data best. This suggests that the relative localization judgment is performed at a stage of visual processing in which retinal and nonretinal information is available.

Goal-dependent automatic processing of potency: A potency-priming paradigm

Valence, arousal and potency can be conceived of as basic dimensions of meaning that are frequently activated. As an effect of frequent usage, research on evaluative priming has demonstrated that valence can be processed automatically. The present study addresses the question of whether potency as a frequently processed dimension is automatically activated, too. In four experiments we employed a category priming procedure with response window technique to test the assumption that shortly presented primes automatically influence responses to targets and/or the encoding of targets. Stimuli varying in potency (i.e., high vs. low potency) were presented as primes and targets with a short stimulus onset asynchrony (30 ms) whereas potency was the task-relevant stimulus feature. In Experiments 1a/b, participants conducted a strong-weak categorization on adjectives varying in potency and valence (Experiment 1a) or potency and arousal (Experiment 1b). In Experiment 2, we examined if novel primes also contribute to the potency priming effect. In Experiment 3, we tried to replicate the effect of novel primes and tested if potency-priming depends on the task. Results across all experiments revealed higher rates of correct responses on trials where prime and target were compatible in terms of their potency compared to trials with incompatible prime-target combinations. Since the priming effect emerges for novel primes, too, it is likely that prime potency is processed automatically. Moreover, the fact that potency priming was modulated by the task-goal further highlights the automaticity of this process.

Visual experience forms a multidimensional pattern that is not reducible to a single measure: Evidence from metacontrast masking.

A metacontrast masking paradigm was employed to provide evidence for the richness and diversity of our visual experience. Square- and diamond-shaped targets were followed by square- and diamond-shaped masks at varying stimulus onset asynchronies (SOAs), resulting in shape-congruent and shape-incongruent trials. In Experiment 1, participants reported in each trial how they perceived target and mask. After extended training, seven different aspects of the target could be distinguished as specific percepts in this metacontrast masking paradigm. These percepts encompass aspects including the temporal distance between both stimuli, the perceived contrast of the target, and motion percepts resulting from the interplay between the target and mask. Participants spontaneously reported each of these percepts, and the frequency of reports varied systematically with SOA and the congruency between target and mask. In Experiment 2, we trained a new group of participants to distinguish each of these target percepts. Again, the frequency of reports of the specific percepts varied with SOA and congruency, just as in Experiment 1. In a last session, we measured objective discrimination performance yielding the typical individually different masking functions across SOAs. An examination of the relation between the frequencies of reports of subjective percepts and objective discrimination performance revealed multiple dissociations between these measures. Results suggest a multidimensional pattern of subjective experiences under metacontrast, which is reflected in dissociated subjective and objective measures of visual awareness. As a consequence, awareness cannot be assessed exhaustively by a single measure, thus challenging the use of simple one-dimensional subjective or objective measures in visual masking.

Visual experience forms a multidimensional pattern that is not reducible to a single measure: Evidence from metacontrast masking

A metacontrast masking paradigm was employed to provide evidence for the richness and diversity of our visual experience. Square- and diamond-shaped targets were followed by square- and diamond-shaped masks at varying stimulus onset asynchronies (SOAs), resulting in shape-congruent and shape-incongruent trials. In Experiment 1, participants reported in each trial how they perceived target and mask. After extended training, seven different aspects of the target could be distinguished as specific percepts in this metacontrast masking paradigm. These percepts encompass aspects including the temporal distance between both stimuli, the perceived contrast of the target, and motion percepts resulting from the interplay between the target and mask. Participants spontaneously reported each of these percepts, and the frequency of reports varied systematically with SOA and the congruency between target and mask. In Experiment 2, we trained a new group of participants to distinguish each of these target percepts. Again, the frequency of reports of the specific percepts varied with SOA and congruency, just as in Experiment 1. In a last session, we measured objective discrimination performance yielding the typical individually different masking functions across SOAs. An examination of the relation between the frequencies of reports of subjective percepts and objective discrimination performance revealed multiple dissociations between these measures. Results suggest a multidimensional pattern of subjective experiences under metacontrast, which is reflected in dissociated subjective and objective measures of visual awareness. As a consequence, awareness cannot be assessed exhaustively by a single measure, thus challenging the use of simple one-dimensional subjective or objective measures in visual masking.

The Effect of Probabilistic Context on Implicit Temporal Expectations in Down Syndrome.

One of the most important sources of predictability that human beings can exploit to create an internal representation of the external environment is the ability to implicitly build up subjective statistics of events’ temporal structure and, consequently, use this knowledge to prepare for future actions. Stimulus expectancy can be subjectively shaped by hierarchically nested sources of prediction, capitalizing on either local or global probabilistic rules. In order to better understand the nature of local-global proactive motor control in Down Syndrome, in the present study a group of participants with Down Syndrome (DS group; n = 28; mean age 29.5 ± 13 years; range 10–54) and a group of typically developing participants matched by either gender or mental age (TD-MA group; n = 28; 5.6 ± 1 years; range 4–8) were administered a novel motor preparation task, defined as the Dynamic Temporal Prediction (DTP) task. In the DTP, the temporal preparation to imperative stimuli is implicitly shaped by the local increase of expectancy. This is manipulated trial-by-trial as a function of the preparatory foreperiod interval (Stimulus-Onset Asynchrony or SOA). In addition, temporal preparation can be also implicitly adjusted as a function of global predictive context, so that a block-wise SOA-distribution bias toward a given preparatory interval might determine a high-order source of expectancy, with functional consequences on proactive motor control adjustment. Results showed that in both groups motor preparation was biased by temporal expectancy when this was locally manipulated within-trials. By contrast, only the TD-MA group was sensitive to global rule changes: only in this cohort was behavioral performance overall impacted by the SOA probabilistic distribution manipulated between-blocks. The evidence of a local-global dissociation in DS suggests that the use of flexible cognitive mechanisms to implicitly extract high-order probabilistic rules in order to build-up an internal model of the temporal properties of events is disrupted in this developmental disorder. Moreover, since the content of the information to be processed in the DTP task was neither verbal nor spatial, we suggest that atypical global processing in Down Syndrome is a domain-general rather than specific aspect characterizing the cognitive profile of this population.

The influence of rhythm on detection of auditory and vibrotactile asynchrony

The perception of an event is strongly influenced by the context in which it occurs. Here, we examined the effect of a rhythmic context on detection of asynchrony in both the auditory and vibrotactile modalities. Using the method of constant stimuli and a two-alternative forced choice (2AFC), participants were presented with pairs of pure tones played either simultaneously or with various levels of stimulus onset asynchrony (SOA). Target stimuli in both modalities were nested within either: (i) a regularly occurring, predictable rhythm (ii) an irregular, unpredictable rhythm, or (iii) no rhythm at all. Vibrotactile asynchrony detection had higher thresholds and showed greater variability than auditory asynchrony detection in general. Asynchrony detection thresholds for auditory targets but not vibrotactile targets were significantly reduced when the target stimulus was embedded in a regular rhythm as compared to no rhythm. Embedding within an irregular rhythm produced no such improvement. The observed modality asymmetries are interpreted with regard to the superior temporal resolution of the auditory system and specialized brain circuitry supporting auditory–motor coupling.

Where and when to look: Sequential effects at the millisecond level

Learning and imitating a complex motor action requires to visually follow complex movements, but conscious perception seems too slow for such tasks. Recent findings suggest that visual perception has a higher temporal resolution at an unconscious than at a conscious level. Here we investigate whether high-temporal resolution in visual perception relies on prediction mechanisms and attention shifts based on recently experienced sequences of visual information. To that aim we explore sequential effects during four different simultaneity/asynchrony discrimination tasks. Two stimuli are displayed on each trial with varying stimulus onset asynchronies (SOA). Subjects decide whether the stimuli are simultaneous or asynchronous and give manual responses. The main finding is an advantage for different-order over same-order trials, when subjects decided that stimuli had been simultaneous on Trial t - 1 , and when Trial t is with an SOA slightly larger than Trial t - 1, or equivalent. The advantage for different-order trials disappears when the stimuli change eccentricity but not direction between trials (Experiment 2), and persists with stimuli displayed in the centre and unlikely to elicit a sense of direction (Experiment 4). It is still observed when asynchronies on Trial t - 1 are small and undetected (Experiment 3). The findings can be explained by an attention shift that is precisely planned in time and space and that incidentally allows subjects to detect an isolated stimulus on the screen, thus helping them to detect an asynchrony.

Are alpha oscillations instrumental in multisensory synchrony perception?

Different inputs from a multisensory object or event are often integrated into a coherent and unitary percept, despite differences in sensory formats, neural pathways, and processing times of the involved modalities. Presumably, multisensory integration occurs if the cross-modal inputs are presented within a certain window of temporal integration where inputs are perceived as being simultaneous. Here, we examine the role of ongoing neuronal alpha (i.e. 10-Hz) oscillations in multimodal synchrony perception.While EEG was measured, participants performed a simultaneity judgement task with visual stimuli preceding auditory ones. At stimulus onset asynchronies (SOA’s) of 160–200 ms, simultaneity judgements were around 50%. For trials with these SOA’s, occipital alpha power was smaller preceding correct judgements, and the individual alpha frequency was correlated with the size of the temporal window of integration. In addition, simultaneity judgements were modulated as a function of oscillatory phase at 12.5 Hz, but the latter effect was only marginally significant.These results support the notion that oscillatory neuronal activity in the alpha frequency range, which has been taken to shape perceptual cycles, is instrumental in multisensory perception.

When adding is right: Temporal order judgements reveal spatial attention shifts during two-digit mental arithmetic.

Recent research suggests that addition and subtraction induce horizontal shifts of attention. Previous studies used single-digit (1d) problems or verification paradigms that lend themselves to alternative solution strategies beyond mental arithmetic. To measure spatial attention during the active production of solutions to complex two-digit arithmetic problems (2d) without manual motor involvement, we used a temporal order judgement (TOJ) paradigm in which two lateralised targets were sequentially presented on screen with a varying stimulus onset asynchrony (SOA). Participants verbally indicated which target appeared first. By varying the delay between the arithmetic problem presentation and the TOJ task, we investigated how arithmetically induced attention shifts develop over time (Experiment 1, n = 31 and Experiment 2, n = 58). In Experiment 2, we additionally varied the carry property of the arithmetic task to examine how task difficulty modulates the effects. In the arithmetic task, participants were first presented with the arithmetic problem via headphones and performed the TOJ task after the delay before responding to the arithmetic task. To account for spontaneous attentional biases, a baseline TOJ was run without arithmetic processing. Both experiments revealed that addition induces shifts of spatial attention to the right suggesting that visuospatial attention mechanisms are recruited during complex arithmetic. We observed no difference in spatial attention between the carry and noncarry condition (Experiment 2). No shifts were observed for subtraction problems. No common and conclusive influence of delay was observed across experiments. Qualitative differences between addition and subtraction and the role of task difficulty are discussed.

Cross-modal psychological refractory period in vision, audition, and haptics.

People's parallel-processing ability is limited, as demonstrated by the psychological refractory period (PRP) effect: The reaction time to the second stimulus (RT2) increases as the stimulus onset asynchrony (SOA) between two stimuli decreases. Most theoretical models of PRP are independent of modalities. Previous research on PRP mainly focused on vision and audition as input modalities; tactile stimuli have not been fully explored. Research using other paradigms and involving tactile stimuli, however, found that dual-task performance depended on input modalities. This study explored PRP with all the combinations of input modalities. Thirty participants judged the magnitude (small or large) of two stimuli presented in different modalities with an SOA of 75-1,200 ms. PRP effect was observed, i.e., RT2 increased with a decreasing SOA, in all the modalities. Only in the auditory-tactile condition did the accuracy of Task 2 decrease with a decreasing SOA. In the auditory-tactile and tactile-visual conditions, RT to the first stimulus also increased with a decreasing SOA. Current models could only explain part of the results, and modality characteristics help to explain the overall data pattern better. Limitations and directions for future studies regarding reaction time, task difficulty, and response modalities are discussed.

Electrophysiological examination of response-related interference while dual-tasking: is it motoric or attentional?

The possibility that interference between motor responses contributes to dual-task costs has long been neglected, yet is supported by several recent studies. There are two competing hypotheses regarding this response-related interference. The motor-bottleneck hypothesis asserts that the motor stage of Task 1 triggers a refractory period that delays the motor stage of Task 2. The response-monitoring hypothesis asserts that monitoring of the Task-1 motor response delays the response-selection stage of Task 2. Both hypotheses predict lengthening of Task-2 response time (RT2) when Task 1 requires motor processing relative to when it does not. However, they assume different loci for the response-related bottleneck, and therefore make different predictions regarding (a) the interaction between Task-1 motor requirement and the Task-2 difficulty effect as measured by RT2 and (b) the premotoric durations and motoric durations of Task 2 as measured by lateralized readiness potentials (LRPs). To test these predictions, we conducted two experiments manipulating the Task-1 motor requirement (Go vs. NoGo) and Task-2 response-selection difficulty, as well as the stimulus-onset asynchrony (SOA). Task-1 motor processing significantly lengthened RT2, suggesting response-related interference. Importantly, the Task-1 motor response reduced the Task-2 difficulty effect at the short SOA, indicating postponement of the Task-2 motor stage, consistent with the motor-bottleneck hypothesis. Further consistent with the motor-bottleneck hypothesis, the Task-2 LRP indicated a consistent premotoric duration of Task 2 regardless of Task-1 motor requirement. These results are difficult to reconcile with the response-monitoring hypotheses, which places the response-related bottleneck before the response-selection stage of Task 2. The results also have important implications regarding use of locus-of-slack logic in PRP studies.

Cueing effects emerge when humans (Homo sapiens) view images of mammals (mammalia) and birds (aves).

Humans use eye- and head-gaze cues to facilitate social interactions among members of their own species. Research examining nonhuman animal-to-human cueing effects has received little attention, but may provide valuable insight into the mechanisms that have enabled species to coexist and thrive in shared environments. The objective of the current studies was to determine how gaze cues influence the attention and target detection of humans when they view images of mammals (human, orangutan, and dog; Experiment 1) and aves (owl, macaw parrot, and duck; Experiment 2). Participants were presented with an image of a forward-facing head that was suddenly replaced with an image of the head facing to the left or right, creating an apparent head rotation and change of orientation. A target appeared randomly on the left or right side of the head-gaze cue after 1 of 4 stimulus-onset asynchronies (SOAs; 100, 300, 600, or 1,000 ms). Participants were asked to indicate the location of the target by pressing a spatially corresponding key. The analysis of response times (RTs) revealed facilitatory cueing effects (RTs to cued targets were shorter than to uncued targets) across all SOAs in Experiment 1 (images of mammals). Such facilitatory cueing effects were only present at short SOAs (i.e., 100 and 300 ms) in Experiment 2 (images of aves). These findings provide initial evidence that the processing of gaze cues observed during human-to-human interactions is similar to that observed during mammal-to-human interactions, but is different in aves-to-human interactions. Alternative interpretations of the data are discussed. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Late disruption of central visual field disrupts peripheral perception of form and color.

Evidence from neuroimaging and brain stimulation studies suggest that visual information about objects in the periphery is fed back to foveal retinotopic cortex in a separate representation that is essential for peripheral perception. The characteristics of this phenomenon have important theoretical implications for the role fovea-specific feedback might play in perception. In this work, we employed a recently developed behavioral paradigm to explore whether late disruption to central visual space impaired perception of color. In the first experiment, participants performed a shape discrimination task on colored novel objects in the periphery while fixating centrally. Consistent with the results from previous work, a visual distractor presented at fixation ~100ms after presentation of the peripheral stimuli impaired sensitivity to differences in peripheral shapes more than a visual distractor presented at other stimulus onset asynchronies. In a second experiment, participants performed a color discrimination task on the same colored objects. In a third experiment, we further tested for this foveal distractor effect with stimuli restricted to a low-level feature by using homogenous color patches. These two latter experiments resulted in a similar pattern of behavior: a central distractor presented at the critical stimulus onset asynchrony impaired sensitivity to peripheral color differences, but, importantly, the magnitude of the effect was stronger when peripheral objects contained complex shape information. These results show a behavioral effect consistent with disrupting feedback to the fovea, in line with the foveal feedback suggested by previous neuroimaging studies.

Using Transcranial Magnetic Stimulation to Test a Network Model of Perceptual Decision Making in the Human Brain.

Previous research has suggested that the lateral occipital cortex (LOC) is involved with visual decision making, and specifically with the accumulation of information leading to a decision. In humans, this research has been primarily based on imaging and electroencephalography (EEG), and as such only correlational. One line of such research has led to a model of three spatially distributed brain networks that activate in temporal sequence to enable visual decision-making. The model predicted that disturbing neural processing in the LOC at a specific latency would slow object decision-making, increasing reaction time (RT) in a difficult discrimination task. We utilized transcranial magnetic stimulation (TMS) to test this prediction, perturbing LOC beginning at 400 ms post-stimulus onset, a time in the model corresponding to LOC activation at a particular difficulty level, with the expectation of increased RT. Thirteen healthy adults participated in two TMS sessions in which left and right LOC were stimulated separately utilizing neuronavigation and robotic coil guidance. Participants performed a two-alternative forced-choice task selecting whether a car or face was present on each trial amidst visual noise pre-tested to approximate a 75% accuracy level. In an effort to disrupt processing, pairs of TMS pulses separated by 50 ms were presented at one of five stimulus onset asynchronies (SOAs): −200, 200, 400, 450, or 500 ms. Behavioral performance differed systematically across SOAs for RT and accuracy measures. As predicted, TMS at 400 ms resulted in a significant slowing of RT. TMS delivered at −200 ms resulted in faster RT, indicating early stimulation may result in priming and performance enhancement. Use of TMS thus causally demonstrated the involvement of LOC in this task, and more broadly with perceptual decision-making; additionally, it demonstrated the role of TMS in testing well-developed neural models of perceptual processing.

Visual and central attention share a capacity limitation when the demands for serial item selection in visual search are high.

Visual and central attention are limited in capacity. In conjunction search, visual attention is required to select the items and to bind their features (e.g., color, form, size), which results in a serial search process. In dual-tasks, central attention is required for response selection, but because central attention is limited in capacity, response selection can only be carried out for one task at a time. Here, we investigated whether visual and central attention rely on a common or on distinct capacity limitations. In two dual-task experiments, participants completed an auditory two-choice discrimination Task 1 and a conjunction search Task 2 that were presented with an experimentally modulated temporal interval between them (stimulus onset asynchrony [SOA]). In Experiment 1, Task 2 was a triple conjunction search task. Each item consisted of a conjunction of three features, so that target and distractors shared two features. In Experiment 2, Task 2 was a plus conjunction search task, in which target and distractors shared the same four features. The hypotheses for conjunction search time were derived from the locus-of-slack method. While plus conjunction search was performed after response selection in Task 1, a small part of triple conjunction search was still performed in parallel to response selection in Task 1. However, the between-experiment comparison was not significant, indicating that both search tasks may require central attention. Taken together, the present study provides evidence that visual and central attention share a common capacity limitation when conjunction search relies strongly on serial item selection.

Global-local processing and dispositional bias interact with emotion processing in the psychological refractory period paradigm.

The reciprocal link between scope of attention and emotional processing is an important aspect of the relationship between emotion and attention. Larger scope of attention or global processing has been linked to positive emotions and narrow scope of attention or local processing has been linked to negative emotions. The nature of this relationship in the context of central capacity limitations and individual differences in attentional processing has not been studied in detail so far. To investigate such a relationship, here we used the psychological refractory period (PRP) paradigm, in which we manipulated the stimulus onset asynchrony (SOA: 150ms, 300ms, 900ms) of stimuli corresponding to two tasks in a sequence. The first task was identifying a number at the global or local level; the second task was recognizing the emotional expression (happy or angry). Additionally, predisposition towards local or global perceptual dimension was measured with the global-local task. Results indicated that global precedence modulated PRP effect and that response accuracy was impaired by the combination of local-angry task modalities. Interestingly, interference between simultaneous tasks was modulated by the predisposition to different perceptual levels resulting in different cognitive strategies for performing simultaneous tasks: locally biased subjects tended more towards serial processing, meanwhile globally biased ones were performing tasks in a parallel manner. This result suggest that individual differences may play a role in the choice of dual-task performing strategies.

Reduced response inhibition after exposure to drug-related cues in male heroin abstainers.

Deficits in response inhibition associated with heroin use could last several months after abstinence in heroin users, and their response inhibition can also be interfered with task-irrelevant drug-related cues. However, it is unclear whether exposure to drug-related cues affects subsequent response inhibition in heroin users following abstinence. The present study aimed to investigate how drug-related cues with different durations between stimulus presentations, referred to as stimulus onset asynchronies (SOAs), affect subsequent response inhibition in heroin abstainers (HAs) with different length of abstinence. Sixty-seven male HAs performed a modified Go/NoGo task in which a motor response to frequent Go targets and no response to rare NoGo targets were required and a Go or NoGo target was displayed after either a heroin-related or a neutral picture presented for the 200ms and 600ms SOAs. The HAs responded significantly faster to Go targets following the neutral pictures for the 600ms SOA compared to other conditions. They also made more commission errors following heroin-related pictures compared to neutral pictures regardless of the SOAs. The shorter-term HAs made more commission errors compared to the longer-term HAs following the 200ms SOA, and it was only a trend when the SOA was 600ms. Additionally, negative correlations between the duration of current abstinence and commission errors were observed following cues with the 200ms SOA. Impaired response inhibition in HAs can be improved through protracted drug abstinence. However, that effect can be reduced by exposure to drug-related cues, which may increase the risk of relapse.

Impaired auditory sensory memory in Cystinosis despite typical sensory processing: A high-density electrical mapping study of the mismatch negativity (MMN).

Cystinosis, a genetic rare disease characterized by cystine accumulation and crystallization, results in significant damage in a multitude of tissues and organs, such as the kidney, thyroid, eye, and brain. While Cystinosis' impact on brain function is relatively mild compared to its effects on other organs, the increased lifespan of this population and thus potential for productive societal contributions have led to increased interest on the effects on brain function. Nevertheless, and despite some evidence of structural brain differences, the neural impact of the mutation is still not well characterized. Here, using a passive duration oddball paradigm (with different stimulus onset asynchronies (SOAs), representing different levels of demand on memory) and high-density electrophysiology, we tested basic auditory processing in a group of 22 children and adolescents diagnosed with Cystinosis (age range: 6-17 years old) and in neurotypical age-matched controls (N=24). We examined whether the N1 and mismatch negativity (MMN) significantly differed between the groups and if those neural measures correlated with verbal and non-verbal IQ. Individuals diagnosed with Cystinosis presented similar N1 responses to their age-matched peers, indicating typical basic auditory processing in this population. However, whereas both groups showed similar MMN responses for the shortest (450ms) SOA, suggesting intact change detection and sensory memory, individuals diagnosed with Cystinosis presented clearly reduced responses for the longer (900ms and 1800ms) SOAs. This could indicate reduced duration auditory sensory memory traces, and thus sensory memory impairment, in children and adolescents diagnosed with Cystinosis. Future work addressing other aspects of sensory and working memory is needed to understand the underlying bases of the differences described here, and their implication for higher order processing.

Независимость простой зрительно-моторной реакции от предсознательной компоненты ощущения при обратной маскировке двухцветными стимулами

The model of visual backward masking in its two-color modification is applicable in the study of the mechanisms of conjugation of the processes of sensory sensation formation and realization of sensorimotor reactions. The effect of the full (100 %) two-color backward masking is reliably implemented with the following values of its parameters: the duration of the test stimulus (red and green) is 0 ms, the stimulus masker (blue) is 45 ms, and the stimulus onset asynchrony (SOA) is 0.1 — 25 ms. In the range of SOA values from 25 to 35 ms, the efficiency of backward masking decreases to 14 %, and with an SOA of 40 ms, it completely disappears. The stimulus detection time (sDT) as part of a simple visual-motor reaction in the paradigm of the model of two-color backward masking does not depend on its effectiveness, the color of the test stimulus, the value of asynchrony in the range (0 — 40 ms), the duration of the stimulus-masker in the formation of a conscious light sensation. A comparative analysis of the stimulus detection time values under the conditions of full (100 %) backward masking and in its absence suggests that the mechanism of the two-color backward masking not associated with photoreceptors, but is implemented in the central parts of the visual analyzer.