Correct Rejection Trials Research Articles

Monetary reward enhances response inhibition processes manifested in No-go P3

This study investigated the impact of motivational valence on No-go P3 and N2 by incorporating monetary rewards based on response outcomes. We also investigated how personality differences in terms of the behavioral inhibition system (BIS) and behavioral approach system (BAS) influenced No-go N2 and No-go P3. Twenty-eight participants performed Go/No-go tasks (80 % Go and 20 % No-go) under two conditions. In the reward condition, each correct-rejection trial for the No-go stimulus was rewarded with 10 yen (∼6 cents), whereas in the neutral condition, neither monetary rewards nor punishments were contingent on response outcomes. Individual responsiveness to punishment and rewards was evaluated using the BIS and BAS scales. The error rate was significantly lower in the reward condition than in the neutral condition. P3 amplitude for correct-rejection trials (i.e., preceding erroneous muscular activity on the wrong hand) was larger in the reward condition than in the neutral condition; however, N2 amplitudes did not differ between the two conditions. These results suggest that monetary rewards may enhance motor inhibition control. Individuals with a higher BIS score exhibited a larger No-go N2 for correct-rejection in the neutral condition. We conclude that No-go N2 amplitude is modulated by avoidance motivation.

An investigation of how relative precision of target encoding influences metacognitive performance

Detection failures in perceptual tasks can result from different causes: sometimes we may fail to see something because perceptual information is noisy or degraded, and sometimes we may fail to see something due to the limited capacity of attention. Previous work indicates that metacognitive capacities for detection failures may differ depending on the specific stimulus visibility manipulation employed. In this investigation, we measured metacognition while matching performance in two visibility manipulations: phase-scrambling and the attentional blink. As in previous work, metacognitive asymmetries emerged: despite matched type 1 performance, metacognitive ability (measured by area under the ROC curve) for reporting stimulus absence was higher in the attentional blink condition, which was mainly driven by metacognitive ability in correct rejection trials. We performed Signal Detection Theoretic (SDT) modeling of the results, showing that differences in metacognition under equal type I performance can be explained when the variance of the signal and noise distributions are unequal. Specifically, the present study suggests that phase scrambling signal trials have a wider distribution (more variability) than attentional blink signal trials, leading to a larger area under the ROC curve for attentional blink trials where subjects reported stimulus absence. These results provide a theoretical basis for the origin of metacognitive differences on trials where subjects report stimulus absence, and may also explain previous findings where the absence of evidence during detection tasks results in lower metacognitive performance when compared to categorization.

The Formation of Symmetrical Gestalts Is Task-Independent, but Can Be Enhanced by Active Regularity Discrimination.

The brain can organize elements into perceptually meaningful gestalts. Visual symmetry is a useful tool to study gestalt formation, and we know that there are symmetry-sensitive regions in the extrastriate cortex. However, it is unclear whether symmetrical gestalt formation happens automatically, whatever the participant's current task is. Does the visual brain always organize and interpret the retinal image when possible, or only when necessary? To test this, we recorded an ERP called the sustained posterior negativity (SPN). SPN amplitude increases with the proportion of symmetry in symmetry + noise displays. We compared the SPN across five tasks with different cognitive and perceptual demands. Contrary to our predictions, the SPN was the same across four of the five tasks but selectively enhanced during active regularity discrimination. Furthermore, during regularity discrimination, the SPN was present on hit trials and false alarm trials but absent on miss and correct rejection trials. We conclude that gestalt formation is automatic and task-independent, although it occasionally fails on miss trials. However, it can be enhanced by attention to visual regularity.

Evoked Frontal and Parietal Field Potential Signatures of Target Detection and Response Inhibition in Rats Performing an Equiprobable Auditory Go/No-Go Task.

To characterize the rat as a potential model of frontal-parietal auditory processing during sustained attention, target detection, and response inhibition, we recorded field potentials (FPs) at multiple sites in medial-dorsal frontal and posterior parietal cortex simultaneously while rats performed an equiprobable auditory go/no-go discrimination task. Event-related potentials (ERPs) were calculated by averaging tone-triggered FPs across hit, miss, false alarm (FA), and correct rejection (CR) trials separately for each recording session, and five peak amplitudes (termed N1, P2, N2, P3E, and P3L) were extracted from the individual-session ERPs. Comparing peak amplitudes across different trials types indicated a statistically significant amplification of the P2 peak on hit trials that accompanies detection of the target tone prior to the behavioral go response. This result appears analogous to human ERP phenomena during auditory target discrimination. Conversely, the rat P3 responses were not associated with target detection as in the human ERP literature. Likewise, we did not observe the "no-go N2" or "no-go P3" responses reported in the human literature in association with response inhibition, which might reflect differences in task context or a difference in auditory processing between rats and humans. We also present analyses of stimulus-induced spectral power and interarea coherence to characterize oscillatory synchronization which may contribute to ERPs, and discuss possible error-related processing at the N2, P3E, and P3L peaks.

Aftereffects of Cognitively Demanding Acute Aerobic Exercise on Working Memory.

ABSTRACTPurposeThis study examined the aftereffects of cognitively demanding acute aerobic exercise on working memory in middle-age individuals.MethodsIn a within-participants design, middle-age males (n = 28) performed a two-back task to assess working memory before, immediately after, and 30 min after the following three interventions: 1) a rest-cognition intervention, in which they performed a cognitive task on a cycle ergometer without exercising; 2) an exercise-cognition intervention, in which they simultaneously exercised on a cycle ergometer and performed a cognitive task; and 3) an exercise-only intervention, in which they only exercised on a cycle ergometer.ResultsThe exercise-only intervention resulted in increased hit rate and decreased reaction times and intraindividual variability on correct rejection trials, suggesting that simple aerobic exercise had a beneficial impact on working memory. By contrast, the exercise-cognition intervention resulted in increased intraindividual variability on correct rejection trials, which is suggestive of cognitive fatigue resulting from the additional cognitive demands. Such a decline was not observed even in the rest-cognition condition.ConclusionsCognitive fatigue caused by additional cognitive demands during aerobic exercise may cancel beneficial postexercise effects on working memory. Cognitively demanding acute aerobic exercise appears to be less effective than simple aerobic exercise in improving executive function.

Pupil-linked arousal modulates behavior in rats performing a whisker deflection direction discrimination task.

Non-luminance-mediated changes in pupil size have been widely used to index arousal state. Recent animal studies have demonstrated correlations between behavioral state-related pupil dynamics and sensory processing. However, the relationship between pupil-linked arousal and behavior in animals performing perceptual tasks has not been fully elucidated. In the present study, we trained head-fixed rats to discriminate between directions of whisker movements using a Go/No-Go discrimination paradigm while imaging their pupils. Reaction times in this discrimination task were significantly slower than in previously reported detection tasks with similar setup, suggesting that discrimination required an increased cognitive load. We found the pupils dilated for all trials following stimulus presentation. Interestingly, in correct rejection trials, where pupil dilations solely resulted from cognitive processing, dilations were larger for more difficult stimuli. Baseline pupil size before stimulus presentation strongly correlated with behavior, as perceptual sensitivity peaked at intermediate pupil baselines and reaction time was fastest at large baselines. We further explored these relationships by investigating to what extent pupil baseline was predictive of upcoming behavior and found that a Bayesian decoder had significantly greater-than-chance probability in correctly predicting behavioral outcomes. Moreover, the outcome of the previous trial showed a strong correlation with behavior on present trials. Animals were more liberal and faster in responding following hit trials, whereas perceptual sensitivity was greatest following correct rejection trials. Taken together, these results suggest a tight correlation between pupil dynamics, perceptual performance, and reaction time in behaving rats, all of which are modulated by fluctuating arousal state. NEW & NOTEWORTHY In this study, we for the first time demonstrated that head-fixed rats were able to discriminate different directions of whisker movement. Interestingly, we found that the pupil dilated more when discriminating more difficult stimuli, a phenomenon reported in human subjects but not in animals. Baseline pupil size before stimulus presentation was found to strongly correlate with behavior, and a Bayesian decoder had significantly greater-than-chance probability in correctly predicting behavioral outcomes based on the baseline pupil size.

Long-term test-retest reliability of event-related potential (ERP) recordings during treadmill walking using the mobile brain/body imaging (MoBI) approach

Advancements in acquisition technology and signal-processing techniques have spurred numerous recent investigations on the electro-cortical signals generated during whole-body motion. This approach, termed Mobile Brain/Body Imaging (MoBI), has the potential to elucidate the neural correlates of perceptual and cognitive processes during real-life activities, such as locomotion. However, as of yet, no one has assessed the long-term stability of event-related potentials (ERPs) recorded under these conditions. Therefore, the objective of the current study was to evaluate the test-retest reliability of cognitive ERPs recorded while walking. High-density EEG was acquired from 12 young adults on two occasions, separated by an average of 2.3years, as they performed a Go/No-Go response inhibition paradigm. During each testing session, participants performed the task while walking on a treadmill and seated. Using the intraclass correlation coefficient (ICC) as a measure of agreement, we focused on two well-established neurophysiological correlates of cognitive control, the N2 and P3 ERPs. Following ICA-based artifact rejection, the earlier N2 yielded good to excellent levels of reliability for both amplitude and latency, while measurements for the later P3 component were generally less robust but still indicative of adequate to good levels of stability. Interestingly, the N2 was more consistent between walking sessions, compared to sitting, for both hits and correct rejection trials. In contrast, the P3 waveform tended to have a higher degree of consistency during sitting conditions. Overall, these results suggest that the electro-cortical signals obtained during active walking are representative of stable indices of neurophysiological function.

Role of medio-dorsal frontal and posterior parietal neurons during auditory detection performance in rats.

To further characterize the role of frontal and parietal cortices in rat cognition, we recorded action potentials simultaneously from multiple sites in the medio-dorsal frontal cortex and posterior parietal cortex of rats while they performed a two-choice auditory detection task. We quantified neural correlates of task performance, including response movements, perception of a target tone, and the differentiation between stimuli with distinct features (different pitches or durations). A minority of units—15% in frontal cortex, 23% in parietal cortex—significantly distinguished hit trials (successful detections, response movement to the right) from correct rejection trials (correct leftward response to the absence of the target tone). Estimating the contribution of movement-related activity to these responses suggested that more than half of these units were likely signaling correct perception of the auditory target, rather than merely movement direction. In addition, we found a smaller and mostly not overlapping population of units that differentiated stimuli based on task-irrelevant details. The detection-related spiking responses we observed suggest that correlates of perception in the rat are sparsely represented among neurons in the rat's frontal-parietal network, without being concentrated preferentially in frontal or parietal areas.

The dopamine signal in decision-making tasks with stimulus and timing uncertainty

It was long suggested that the phasic activity of midbrain dopamine (DA) neurons codes the subject’s error in the prediction of reward [1]. Most of the experimental work in this field was done in the context of classical and instrumental conditioning. Recently, there has been an increasing interest to study the activity of DA neurons while the subject performs a decision-making task with the goal of obtaining reward at the end of the trial [2,3]. In an experiment in which monkeys have to decide about the presence or absence of a somatosensory stimulus, recordings of DA neurons have shown that the activity of these cells is modulated according to the trial type. The averaged activity in hit, miss, false alarm or correct rejection trials each presents a distinct temporal profile [3]. In particular, the neurons’ response to the go cue is correlated with the subject’s uncertainty about his choice. The signal of dopamine neurons in classical and instrumental conditioning has been explained in terms of the temporal-difference (TD) algorithm. However it is not clear whether and, if so, how reinforcement learning can account for the dopamine signals in complex decision-making tasks with noisy sensory information and temporal uncertainty of the relevant task events, as is the case in the detection task mentioned above [4]. We have developed an actor-critic model which deals with both these aspects of the problem. While an internal temporal representation keeps track of past relevant events, partial observability is accounted for by means of a Bayesian approach. The dopamine phasic activity predicted by the model matches the experimental data and the prediction of the psychometric curve is consistent with the animal performance. Furthermore, the model provides an interpretation of the condition-dependent dopamine response to the go cue instruction in terms of reward prediction error. Using Bayesian inference the model constructs an internal belief about the presence of the somatosensory stimulus. This belief reflects the confidence about the sensory perception and thus the value assigned to this perceptual judgment. The large belief in stimulus-present decisions represents a high degree of confidence in the sensory perception and a great expectation for future rewards. On the contrary, stimulus-absent choices reflect a small belief and consequently a larger uncertainty about the decision and the future reward. This computational description of belief agrees with the previous interpretation of the data [3] and describes well other experimental observations such as the dependence of DA neurons' signals on the stimulus amplitude. The model also predicts a decrease in dopamine activity before the go cue instruction, which is also observed in the data. We explain this decreasing tonic activity as an effect of the timing uncertainty. This is partly due to the task structure and partly generated from the limited temporal resolution of the stimulus representation, which creates subjective variability in the timing of events.

The subjective experience of object recognition: comparing metacognition for object detection and object categorization

Perceptual decisions seem to be made automatically and almost instantly. Constructing a unitary subjective conscious experience takes more time. For example, when trying to avoid a collision with a car on a foggy road you brake or steer away in a reflex, before realizing you were in a near accident. This subjective aspect of object recognition has been given little attention. We used metacognition (assessed with confidence ratings) to measure subjective experience during object detection and object categorization for degraded and masked objects, while objective performance was matched. Metacognition was equal for degraded and masked objects, but categorization led to higher metacognition than did detection. This effect turned out to be driven by a difference in metacognition for correct rejection trials, which seemed to be caused by an asymmetry of the distractor stimulus: It does not contain object-related information in the detection task, whereas it does contain such information in the categorization task. Strikingly, this asymmetry selectively impacted metacognitive ability when objective performance was matched. This finding reveals a fundamental difference in how humans reflect versus act on information: When matching the amount of information required to perform two tasks at some objective level of accuracy (acting), metacognitive ability (reflecting) is still better in tasks that rely on positive evidence (categorization) than in tasks that rely more strongly on an absence of evidence (detection).

Neural correlates of an illusory touch experience investigated with fMRI

When asked to judge the presence or absence of near-threshold tactile stimuli, participants often report touch experiences when no tactile stimulation has been delivered (‘false alarms’). The simultaneous presentation of a light flash during the stimulation period can increase the frequency of touch reports, both when touch is and is not present. Using fMRI, we investigated the BOLD response during both light-present and light-absent false alarms, testing predictions concerning two possible neural mechanisms underlying these illusory touch experiences: activation of a tactile representation in primary somatosensory cortex (SI) and/or activation of a tactile representation in late processing areas outside of sensory-specific cortex, such as medial prefrontal cortex (MPC). Our behavioural results showed that participants made false alarms in light-present and light-absent trials, both of which activated regions of the medial parietal and medial prefrontal cortex including precuneus, posterior cingulate and paracingulate cortex, suggesting the same underlying mechanism. However, only a non-significant increase in SI activity was measured in response to false alarm vs. correct rejection trials. We argue that our results provide evidence for the role of top-down regions in somatic misperception, consistent with findings from studies in humans and non-human primates.

Search Termination Time in Visual Search is Determined by Expectation of Target Prevalence

Reaction times for search termination decisions (“no” RTs) are shorter when targets are rarer (lower “target prevalence”). Is this “prevalence effect” a result of the observers' expectation of target prevalence or of repetition priming from repeated “no” responses? If number of repetitions determines “no” RTs, independent of target prevalence, evidence would favor a repetition priming account. In contrast, if implicit or explicit knowledge of the target prevalence determines “no” RTs, regardless of repetitions, evidence would favor an expectation account. In experiment 1, we conducted visual search tasks where prevalence varied across blocks, and analyzed correct rejection trials in time series. The main effect of number of repetitions was not statistically significant, but the main effect of target prevalence was statistically significant. In experiment 2, high-prevalence and low-prevalence trials were randomly mixed and the prevalence for the next trial was cued. The result showed that the “no” RTs in the low prevalence trials were still faster than those on high prevalence trials. These results suggest that the prevalence effect on the “no” RTs is the result of the expectation of target prevalence.

Subjective discriminability of invisibility: A framework for distinguishing perceptual and attentional failures of awareness

Conscious visual perception can fail in many circumstances. However, little is known about the causes and processes leading to failures of visual awareness. In this study, we introduce a new signal detection measure termed subjective discriminability of invisibility (SDI) that allows one to distinguish between subjective blindness due to reduction of sensory signals or to lack of attentional access to sensory signals. The SDI is computed based upon subjective confidence in reporting the absence of a target (i.e., miss and correct rejection trials). Using this new measure, we found that target misses were subjectively indistinguishable from physical absence when contrast reduction, backward masking and flash suppression were used, whereas confidence was appropriately modulated when dual task, attentional blink and spatial uncertainty methods were employed. These results show that failure of visual perception can be identified as either a result of perceptual or attentional blindness depending on the circumstances under which visual awareness was impaired.

Brain mechanisms for mood congruent memory facilitation

Emotional information is better remembered when mood at the time of retrieval matches it in valence (positive mood, positive material). An associative memory model predicts that this ‘mood congruent’ facilitation is due to the mood-related reactivation at retrieval of emotional responses which were linked to valenced information at encoding. To test this model, we presented subjects with positive and negative words at study and manipulated their mood at test while using functional imaging to monitor brain activity. Subjective mood ratings and heart rate variability both indicated that the manipulation was effective, and memory performance showed a strong trend towards facilitation in congruent conditions. In the functional imaging data, valence-specific conjunctions between encoding activity predicting subsequent memory in a congruent mood and retrieval activity relating to mood congruent recollection revealed shared responses in subgenual cingulate for positive valence and posteriolateral orbitofrontal cortex for negative valence, thus supporting the associative model. To elucidate the mnemonic basis of facilitation, independent of valence, we examined the shared correlates of positive and negative congruence and found that parts of the episodic memory system were activated by congruence in correct rejection trials, but no part of this system was activated by congruence in correctly remembered trials. This pattern suggests that mood congruent facilitation occurs at the level of attempted recall rather than that of successful recollection.

Neural Correlates of Episodic Retrieval Success

Episodic memory retrieval involves multiple component processes, including those that occur when information is correctly remembered (retrieval success). The present study employed rapid-presentation event-related functional MRI that allowed different trial types with short intertrial intervals to be sorted such that the hemodynamic response associated with retrieval success could be extracted. Specifically, in an old/new episodic recognition task, hit trials (correctly recognized old items) and correct rejection trials (correctly rejected new items) were directly compared. The comparison revealed a mostly left-lateralized set of brain regions. Differential activation was most robust in left lateral parietal cortex and medial parietal cortex. Additional regions of differential activation included left anterior prefrontal cortex at or near Brodmann area 10, anterior insula, thalamus, anterior cingulate cortex, frontal cortex along inferior frontal gyrus, premotor cortex, and presupplementary motor area. These results suggest that left frontal and parietal regions modulate activity based on the successful retrieval of information from episodic memory. We discuss these findings in the context of several recent investigations that provide converging results as well as prior studies that have failed to detect these changes.

Emitted P300 and slow wave event-related potentials in guessing and detection tasks

A comparison was made of evoked and emitted P300 and Slow Wave activity elicited in guessing and signal detection tasks. The stimulus conditions were the same in both tasks. Only the instructions to the subjects were different. Latency corrected averaging was used to compensate for trial-to-trial fluctuation of P300 latency. Principal components-varimax analysis (PCVA) was utilized to deal with overlap among P300, Slow Wave and CNV return-to-baseline Clear measures (from both conventional and latency corrected averages) of emitted P300 components for correct rejection trials were obtained under the following conditions: (a) stimulus intensity near threshold ( detection accuracy ≊ 78%, d′≊ 1.9 ); (b) no simultaneous cueing signal; (c) stimulus presence and absence were equiprobable; (d) estimated contributions of overlap from other event-related potential components were removed from the P300 measurements. A significant difference was found between the Slow Wave topographic profiles elicited in the guessing and detection tasks. For the guessing task Slow Wave was relatively large and positive at vertex whereas in the detection task it was near zero amplitude at vertex. No significant differences due to task were found for the P300s when a PCVA derived estimate of the contribution of Slow Wave overlap was removed from the P300 measures.