Irrelevant Stimulus Dimensions Research Articles

In-channel cancellation: A model of early auditory processing.

A model of early auditory processing is proposed in which each peripheral channel is processed by a delay-and-subtract cancellation filter, tuned independently for each channel with a criterion of minimum power. For a channel dominated by a pure tone or a resolved partial of a complex tone, the optimal delay is its period. For a channel responding to harmonically related partials, the optimal delay is their common fundamental period. Each peripheral channel is thus split into two subchannels-one that is cancellation-filtered and the other that is not. Perception can involve either or both, depending on the task. The model is illustrated by applying it to the masking asymmetry between pure tones and narrowband noise: a noise target masked by a tone is more easily detectable than a tone target masked by noise. The model is one of a wider class of models, monaural or binaural, that cancel irrelevant stimulus dimensions to attain invariance to competing sources. Similar to occlusion in the visual domain, cancellation yields sensory evidence that is incomplete, thus requiring Bayesian inference of an internal model of the world along the lines of Helmholtz's doctrine of unconscious inference.

Developmental changes in impulse control: Trial-by-trial EMG dissociates the evolution of impulse strength from its subsequent suppression.

Goal-oriented behavior can be disrupted by irrelevant information that automatically activates incorrect responses. While behavioral errors reveal response capture in such situations, they are only the tip of the iceberg. Additional subliminal activations of the incorrect responses (partial errors) can be revealed on correctly responded trials thanks to electromyography (EMG). In the current study, for the first time, EMG recorded in children was combined with distributional analyses. This allowed to investigate the properties of incorrect response activations and to highlight developmental changes in impulse control. A sample of 114 children aged 6-14 years was studied. Children performed a Simon task in which the irrelevant stimulus-position automatically activates a response that might be compatible or incompatible with the correct one. On incompatible trials, the automatic response activation must be overcome by controlled response selection. As previously observed in adults, our approach revealed the presence of an automatic EMG activation of the incorrect response elicited by the irrelevant stimulus dimension. Further, it revealed another independent source at the origin of incorrect response activations: the tendency to guess for response alternation. Both sources increased the frequency of early incorrect EMG activations, indicating impulsive responding. In addition, the influence of both sources decreased with increasing age. Thus, development is marked by improved ability to manage distractibility on the one hand and decreased tendency to rely on a guessing strategy on the other.

Linear separability, irrelevant variability, and categorization difficulty.

In rule-based (RB) category-learning tasks, the optimal strategy is a simple explicit rule, whereas in information-integration (II) tasks, the optimal strategy is impossible to describe verbally. This study investigates the effects of two different category properties on learning difficulty in category learning tasks-namely, linear separability and variability on stimulus dimensions that are irrelevant to the categorization decision. Previous research had reported that linearly separable II categories are easier to learn than nonlinearly separable categories, but Experiment 1, which compared performance on linearly and nonlinearly separable categories that were equated as closely as possible on all other factors that might affect difficulty, found that linear separability had no effect on learning. Experiments 1 and 2 together also established a novel dissociation between RB and II category learning: increasing variability on irrelevant stimulus dimensions impaired II learning but not RB learning. These results are all predicted by the best available measures of difficulty in RB and II tasks. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Relations Among Anhedonia, Reinforcement Learning, and Global Functioning in Help-seeking Youth.

Dysfunction in the neural circuits underlying salience signaling is implicated in symptoms of psychosis and may predict conversion to a psychotic disorder in youth at clinical high risk (CHR) for psychosis. Additionally, negative symptom severity, including consummatory and anticipatory aspects of anhedonia, may predict functional outcome in individuals with schizophrenia-spectrum disorders. However, it is unclear whether anhedonia is related to the ability to attribute incentive salience to stimuli (through reinforcement learning [RL]) and whether measures of anhedonia and RL predict functional outcome in a younger, help-seeking population. We administered the Salience Attribution Test (SAT) to 33 participants who met criteria for either CHR or a recent-onset psychotic disorder and 29 help-seeking youth with nonpsychotic disorders. In the SAT, participants must identify relevant and irrelevant stimulus dimensions and be sensitive to different reinforcement probabilities for the 2 levels of the relevant dimension ("adaptive salience"). Adaptive salience attribution was positively related to both consummatory pleasure and functioning in the full sample. Analyses also revealed an indirect effect of adaptive salience on the relation between consummatory pleasure and both role (αβ = .22, 95% CI = 0.02, 0.48) and social functioning (αβ = .14, 95% CI = 0.02, 0.30). These findings suggest a distinct pathway to poor global functioning in help-seeking youth, via impaired reward sensitivity and RL.

Differential effects of faces and words in cognitive control in older adults with and without major depressive disorder: An emotional Stroop task study

Aging and major depressive disorders have been associated with impaired cognitive control. These deficits are also influenced by the affective valence and by the type of stimulus processed. Using an emotional Stroop task, the current study aims to examine cognitive control deficits and their association with emotion regulation in depression and the influence of the type of stimulus (words and faces) in this association. A total of 26 older patients with a major depressive disorder (MDD) (19 women; age range: 65–84 years) and 26 older healthy controls (18 women; age range: 65–80 years) participated in the study. The results showed that MDD individuals presented greater Stroop effects than their healthy controls and an absence of the conflict adaptation effect defined as a reduction of the influence of irrelevant stimulus dimensions after incongruent trials. Additionally, our results also showed that the processing of emotional words in depressed participants is more automatic than the processing of emotional faces. These findings suggest that older depressed individuals have greater difficulty in recognizing affective facial expressions than older healthy controls, while the over-learned behavior of word reading greatly reduces differences in the performance of the emotional Stroop task between groups (MDD and healthy controls).

The dynamics of interference control across childhood and adolescence: Distribution analyses in three conflict tasks and ten age groups.

Interference control is central to cognitive control and, more generally, to many aspects of development. Despite its importance, the understanding of the processes underlying mean interference effects across development is still limited. When measured through conflict tasks, mean interference effects reflect both the strength of the initial automatic incorrect response activation by the irrelevant stimulus dimension and the capacity to subsequently suppress this tendency and/or activate the correct response. To investigate the development of interference control, we focused on the time course of these activation and/or suppression processes studied in 360 children distributed in 10 age groups (from 5 to 14 years of age) and 36 adults. Each participant performed the 3 mostly used conflict tasks (Simon, flanker, and Stroop) designed to be sensitive across the whole age range. Performances were analyzed using distribution analyses of accuracy and response times. Conditional accuracy functions highlighted conflict-dependent developmental changes in the time course of the initial incorrect response capture and later controlled correct response activation: These results revealed a mature pattern for Simon from 5 years onward (the easiest task as assessed by fastest reaction time and highest accuracy), late maturation in Stroop (the most difficult task), intermediate in flanker. In contrast, despite the increased speed of responses across the age range, the shape of correct response distributions did not change with age, leaving open the maturation of suppression processes. Results are discussed with respect to the interest of the methodology used and debates on the interpretation of the dynamics at hand. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Low and high stimulation frequencies differentially affect automated response selection in the superior parietal cortex \u2013 implications for somatosensory area processes

Response inhibition as a central facet of executive functioning is no homogeneous construct. Interference inhibition constitutes a subcomponent of response inhibition and refers to inhibitory control over responses that are automatically triggered by irrelevant stimulus dimensions as measured by the Simon task. While there is evidence that the area-specific modulation of tactile information affects the act of action withholding, effects in the context of interference inhibition remain elusive. We conducted a tactile version of the Simon task with stimuli designed to be predominantly processed in the primary (40 Hz) or secondary (150 Hz) somatosensory cortex. On the basis of EEG recordings, we performed signal decomposition and source localization. Behavioral results reveal that response execution is more efficient when sensory information is mainly processed via SII, compared to SI sensory areas during non-conflicting trials. When accounting for intermingled coding levels by temporally decomposing EEG data, the results show that experimental variations depending on sensory area-specific processing differences specifically affect motor and not sensory processes. Modulations of motor-related processes are linked to activation differences in the superior parietal cortex (BA7). It is concluded that the SII cortical area supporting cognitive preprocessing of tactile input fosters automatic tactile information processing by facilitating stimulus-response mapping in posterior parietal regions.

Mood state and conflict adaptation: an update and a diffusion model analysis.

The present study investigated the affective modulation of conflict adaptation. In a first step, we conducted a direct replication of a previous study (Schuch & Pütz, 2018). Positive vs. negative mood state was induced by a success-failure manipulation (between-groups, N = 40 per group). In a subsequent task-switching experiment, the congruency sequence effect was assessed in task repetitions and task switches, measuring conflict adaptation within tasks and between tasks, respectively. We found conflict adaptation (averaged across task repetitions and task switches) to be enhanced in negative mood. We did not replicate our previous finding of enhanced conflict adaptation in task switches in positive mood. In a second step, we combined the replication data with the original data set, yielding a larger database with N = 80 per mood group. Using diffusion modeling, we explored the affective modulation of conflict adaptation in task repetitions. Conflict adaptation was reflected in drift rate, consistent with the idea that response conflict triggers an increase in processing selectivity, thereby attenuating the influence of the irrelevant stimulus dimension. Conflict adaptation was also reflected in boundary separation, suggesting that response conflict on the previous trial triggered an increase in response caution. The mood manipulation did not seem to affect processing selectivity (as captured by drift rate) but affected the setting of response caution (as captured by the boundary separation parameter), with faster and more error-prone responding in the negative than positive mood group. We discuss theoretical implications of these findings, and also briefly consider the affective modulations of other cognitive control measures.

Occipitotemporal representations reflect individual differences in conceptual knowledge.

Through selective attention, decision-makers can learn to ignore behaviorally irrelevant stimulus dimensions. This can improve learning and increase the perceptual discriminability of relevant stimulus information. Across cognitive models of categorization, this is typically accomplished through the inclusion of attentional parameters, which provide information about the importance assigned to each stimulus dimension by each participant. The effect of these parameters on psychological representation is often described geometrically, such that perceptual differences over relevant psychological dimensions are accentuated (or stretched), and differences over irrelevant dimensions are down-weighted (or compressed). In sensory and association cortex, representations of stimulus features are known to covary with their behavioral relevance. Although this implies that neural representational space might closely resemble that hypothesized by formal categorization theory, to date, attentional effects in the brain have been demonstrated through powerful experimental manipulations (e.g., contrasts between relevant and irrelevant features). This approach sidesteps the role of idiosyncratic conceptual knowledge in guiding attention to useful information sources. To bridge this divide, we used formal categorization models, which were fit to behavioral data, to make inferences about the concepts and strategies used by individual participants during decision-making. We found that when greater attentional weight was devoted to a particular visual feature (e.g., “color”), its value (e.g., “red”) was more accurately decoded from occipitotemporal cortex. We also found that this effect was sufficiently sensitive to reflect individual differences in conceptual knowledge, indicating that occipitotemporal stimulus representations are embedded within a space closely resembling that formalized by classic categorization theory.

Attentional state modulates the effect of an irrelevant stimulus dimension on perception.

Covariations of acoustic features provide redundancy in rapidly changing soundscapes: Hearing one feature enables a listener to infer another if these 2 features normally covary. However, it is unknown whether situational demands affect the degree to which covariations influence perceptual inferences. We exploited a perceptual interdependency between modulation rate and frequency and examined, in 6 experiments, whether challenging situations would alter the degree to which people rely on frequency information to make decisions about modulation rate. Participants listened to amplitude-modulated (AM) sounds with modulation rates (∼5 Hz) either decreasing or increasing over time and identified the direction of the rate change. Participants were instructed to ignore carrier frequency, which either decreased or increased (∼1,300 Hz) over time. We observed that participants were more likely to perceive the modulation rate as slowing down when frequency decreased and as speeding up when frequency increased (AM-rate change illusion). The magnitude of the illusion increased when uninformative cues (compared with informative cues) prohibited regulation of attention to sounds, and under distraction introduced by a concurrent visual motion-tracking task. The evidence suggests that the attentional state affects how strongly people rely on featural covariations to make perceptual inferences. (PsycINFO Database Record

Impulsive oculomotor action selection in Parkinson’s disease

The effects of Parkinson's disease (PD) on the dynamics of impulsive action selection and suppression have recently been studied using distributional analyses, but with mixed results, especially for selection. Furthermore, some authors have suggested that impulsivity, regarded as a personality trait, shares common features with behavioral tasks’ measures. The current study was designed to clarify the impact of PD on impulsive action selection and suppression, and investigate the link between cognitive action control and self-reported impulsivity. We administered an oculomotor version of the Simon task to 32 patients with PD and 32 matched healthy controls (HC), and conducted distributional analyses in accordance with the activation-suppression model. Patients and HC also filled out the Barratt Impulsiveness Scale (BIS) questionnaire. Results showed that patients with PD were faster overall and exhibited a greater congruence effect than HC. They also displayed enhanced impulsive action selection. By contrast, the suppression of impulsive responses was similar across both groups. Furthermore, patients had higher impulsivity scores, which were correlated with higher impulsive action selection and higher suppression. Our study yielded two interesting findings. First, PD resulted in a higher number of fast errors. The activation-suppression model suggests that patients with PD are more susceptible to the impulsive action selection induced by the irrelevant stimulus dimension. Second, impulsive action selection and suppression were both associated with trait impulsivity, as measured by the BIS, indicating that these two aspects of impulsivity share common features.

Synchronous beta rhythms of frontoparietal networks support only behaviorally relevant representations.

Categorization has been associated with distributed networks of the primate brain, including the prefrontal cortex (PFC) and posterior parietal cortex (PPC). Although category-selective spiking in PFC and PPC has been established, the frequency-dependent dynamic interactions of frontoparietal networks are largely unexplored. We trained monkeys to perform a delayed-match-to-spatial-category task while recording spikes and local field potentials from the PFC and PPC with multiple electrodes. We found category-selective beta- and delta-band synchrony between and within the areas. However, in addition to the categories, delta synchrony and spiking activity also reflected irrelevant stimulus dimensions. By contrast, beta synchrony only conveyed information about the task-relevant categories. Further, category-selective PFC neurons were synchronized with PPC beta oscillations, while neurons that carried irrelevant information were not. These results suggest that long-range beta-band synchrony could act as a filter that only supports neural representations of the variables relevant to the task at hand.

A critical role for the anterior thalamus in directing attention to task-relevant stimuli.

The prefrontal cortex mediates adaption to changing environmental contingencies. The anterior thalamic nuclei, which are closely interconnected with the prefrontal cortex, are important for rodent spatial memory, but their potential role in executive function has received scant attention. The current study examined whether the anterior thalamic nuclei are involved in attentional processes akin to those of prefrontal regions. Remarkably, the results repeatedly revealed attentional properties opposite to those of the prefrontal cortex. Two separate cohorts of rats with anterior thalamic lesions were tested on an attentional set-shifting paradigm that measures not only the ability of stimuli dimensions that reliably predict reinforcement to gain attention ("intradimensional shift"), but also their ability to shift attention to another stimulus dimension when contingencies change ("extradimensional shift"). In stark contrast to the effects of prefrontal damage, anterior thalamic lesions impaired intradimensional shifts but facilitated extradimensional shifts. Anterior thalamic lesion animals were slower to acquire discriminations based on the currently relevant stimulus dimension but acquired discriminations involving previously irrelevant stimulus dimensions more rapidly than controls. Subsequent tests revealed that the critical determinant of whether anterior thalamic lesions facilitate extradimensional shifts is the degree to which the stimulus dimension has been established as an unreliable predictor of reinforcement over preceding trials. This pattern of performance reveals that the anterior thalamic nuclei are vital for attending to those stimuli that are the best predictors of reward. In their absence, unreliable predictors of reward usurp attentional control.

Attentional control in amnestic MCI subtypes: Insights from a Simon task.

Our aim was to compare attentional control abilities in healthy older subjects and amnestic mild cognitive impairment (aMCI) subtypes. We also analyzed group differences in dynamic changes in performance across the entire reaction time (RT) distribution. Thirty-one multiple domain (mda-MCI), 31 single domain (sda-MCI), and 41 healthy control adults (HC) participated in the study. Participants performed a spatial stimulus-response consistency task in which relevant and irrelevant stimulus dimensions overlapped in the spatial response dimension. We analyzed reaction times (RTs), number of errors (NEs), and omitted responses (ORs), and implemented statistical procedures to neutralize age and processing speed effects. There were no significant RT group differences across consistency conditions. Accuracy (NE) was lower in the mda-MCI group than in HC for inconsistent trials. Distributional analysis revealed increased RT-Simon effect in longer RTs and increased NE-Simon effect in the faster quintiles in a similar way for all groups. NE-Simon effect was greater in the mda-MCI group than in the other groups in the faster quintiles. All groups displayed difficulty in suppression of automatic response pathway and in enacting the deliberate pathway to intentionally control the responses. The greater impairment in the mda-MCI group relative to the other groups is basically quantitative in nature and involves stronger activation of the pathway of automatic response.

Perceiving sequential dependencies in auditory streams

This study examined the ability of human listeners to detect the presence and judge the strength of a statistical dependency among the elements comprising sequences of sounds. The statistical dependency was imposed by specifying transition matrices that determined the likelihood of occurrence of the sound elements. Markov chains were constructed from these transition matrices having states that were pure tones/noise bursts that varied along the stimulus dimensions of frequency and/or interaural time difference. Listeners reliably detected the presence of a statistical dependency in sequences of sounds varying along these stimulus dimensions. Furthermore, listeners were able to discriminate the relative strength of the dependency in pairs of successive sound sequences. Random variation along an irrelevant stimulus dimension had small but significant adverse effects on performance. A much greater decrement in performance was found when the sound sequences were concurrent. Likelihood ratios were computed based on the transition matrices to specify Ideal Observer performance for the experimental conditions. Preliminary modeling efforts were made based on degradations of Ideal Observer performance intended to represent human observer limitations. This experimental approach appears to be useful for examining auditory "stream" formation and maintenance over time based on the predictability of the constituent sound elements.

An event-related potentials study for conflict monitoring in two subtypes of attention deficit hyperactivity disorder in children

Objective To examined differences of conflict monitor function between the inattentive and combined Attention deficit hyperactivity disorder(ADHD) subtypes using event-related potentials(ERP) to assess the degree of cognitive impairment and explore neural mechanisms. Methods ERPs elicited by performing the spatial Simon-Stroop task were recorded in 50 children with ADHD(ADHD/Inattentive, ADHD-I(n=25); ADHD/Combined, ADHD-III(n=25) and 30 normal children.The differences of N2 component of ERP results in three groups were compared and analysed. Results ①Amplitude: ERP data indicated that the amplitude of N2 of the children with ADHD-I and ADHD-III in Simon-incongruent trials(Siin (-4.33±2.89)μV, (-2.49±2.01)μV)and Stroop-inconsistent trials(Stin(-5.03±3.03)μV, (-3.33±1.44)μV) were lower than matched controls (Siin(-6.13±2.93)μV; Stin(-6.58±2.80)μV). ADHD-III children were lower than ADHD-I children, and the difference had statistic significance (P<0.05). ②Latency: the latency of both subtypes of ADHD were longer than controls in Siin(ADHD-I(339.80±31.96)ms, ADHD-III(358.70±22.10)ms, control(325.96±23.01)ms)and Stin(ADHD-I(344.29±26.23)ms, ADHD-III(352.60±17.90)ms, control(331.15±24.62)ms) condition, the difference had statistic significance (P<0.05), ADHD-I children were shorter than ADHD-III children in Siin and Stin condition, but only in Siin condition the difference had statistic significance(P<0.05). Conclusion Conflict monitoring function defect of ADHD-III are more serious than ADHD-I, the ability of identify task relevant stimulus dimensions and resist irrelevant stimulus dimensions or automatic response to task-related stimulus was weaker. The neural mechanisms and congnitive of two subtypes may be different. Key words: Attention deficit hyperactivity disorder; Subtype; Event-related potentials; Conflict monitoring

Influence of Temporal Overlap on Time Course of the Simon Effect

Two experiments are reported in which we manipulated relevant and irrelevant stimulus dimensions to assess whether an increase in temporal overlap would influence the time course of a "standard" Simon effect (obtained when visual stimuli are presented on the left/right of the screen and left/right responses are performed with uncrossed hands). This procedure is new in two ways: First, the manipulations were intended to reduce, instead of increase, the distance between conditional and unconditional response-activation processes. Second, we manipulated the relevant and irrelevant stimulus dimensions in a manner that did not vary stimulus onset asynchronies, precues, or go/no go trials, or alter the stimulus quality. Results were consistent with the hypothesis that when the two response processes are shifted closer to each other, the Simon effect would be sustained across time, instead of decreasing as typically found. These findings are discussed in line with the temporal overlap hypothesis and with an automatic activation account.

Is “conflict adaptation” driven by conflict? Behavioral and EEG evidence for the underappreciated role of congruent trials

Theories of cognitive control argue that response conflict in speeded performance tasks leads to adaptive changes, such that irrelevant information is better ignored on subsequent trials. This study tested whether trial-by-trial changes are driven primarily by conflict on incongruent trials or instead by congruent trials, in which irrelevant and relevant stimulus dimensions match. In a Stroop task including congruent, incongruent, and neutral trials, interference was greater following congruent compared to incongruent and neutral trials, which did not differ. During the intertrial interval, EEG alpha power, an inverse measure of cerebral activation, was significantly lower following congruent than neutral trials, whereas incongruent and neutral trials did not differ. These results imply that trial-by-trial changes in performance may not be driven solely by conflict, but rather by changes in attention triggered by congruent information.

Reduced cognitive flexibility with aging may stem from insufficient suppression of currently irrelevant stimulus dimensions during task-switching

Reduced cognitive flexibility with aging may stem from insufficient suppression of currently irrelevant stimulus dimensions during task-switching

Sequential analysis of the numerical Stroop effect reveals response suppression.

Automatic processing of irrelevant stimulus dimensions has been demonstrated in a variety of tasks. Previous studies have shown that conflict between relevant and irrelevant dimensions can be reduced when a feature of the irrelevant dimension is repeated. The specific level at which the automatic process is suppressed (e.g., perceptual repetition, response repetition), however, is less understood. In the current experiment we used the numerical Stroop paradigm, in which the processing of irrelevant numerical values of 2 digits interferes with the processing of their physical size, to pinpoint the precise level of the suppression. Using a sequential analysis, we dissociated perceptual repetition from response repetition of the relevant and irrelevant dimension. Our analyses of reaction times, error rates, and diffusion modeling revealed that the congruity effect is significantly reduced or even absent when the response sequence of the irrelevant dimension, rather than the numerical value or the physical size, is repeated. These results suggest that automatic activation of the irrelevant dimension is suppressed at the response level. The current results shed light on the level of interaction between numerical magnitude and physical size as well as the effect of variability of responses and stimuli on automatic processing.