The role of perceptual processing in the oddball effect revealed by the Thatcher illusion

When a novel stimulus (oddball) appears after repeated presentation of an identical stimulus, the oddball is perceived to last longer than the repeated stimuli, a phenomenon known as the oddball effect. We investigated whether the perceptual or physical differences between the repeated and oddball stimuli are more important for the oddball effect. To manipulate the perceptual difference while keeping their physical visual features constant, we used the Thatcher illusion, in which an inversion of a face hinders recognition of distortion in its facial features. We found that the Thatcherized face presented after repeated presentation of an intact face induced a stronger oddball effect when the faces were upright than when they were inverted (Experiment 1). However, the difference in the oddball effect between face orientations was not observed when the intact face was presented as the oddball after repeated presentation of a Thatcherized face (Experiment 2). These results were replicated when participants performed both the intact-repeated and Thatcherized-repeated conditions in a single experiment (Experiment 3). Two control experiments confirmed that the repeated presentation of the preceding stimuli is necessary for the difference in duration distortion to occur (Experiments 4 and 5). The results suggest the considerable role of perceptual processing in the oddball effect. We discuss the discrepancy in the results between the intact-repeated and Thatcherized-repeated conditions in terms of predictive coding.

Individual differences in absolute identification as a function of autistic trait levels

The present study aimed to examine the links between a self-report measure known to be discriminative of autism (the AQ-10) and performance on the classic unidimensional absolute identification judgment task with 10 line lengths. The interest in this task is due to the fact that discriminating absolutely between such items is quite perceptually challenging and also that it is not very amenable to generalization. Importantly, there are two currently available views of perceptual learning in autism that suggest that those higher on the autism spectrum might have an advantage on this task. Results showed, however, that for N = 291 typically developing individuals, higher scores on the AQ-10 (and also on a measure of the degree to which individuals self-report having a more spontaneous, activist-type learning style) tended to relate to lower levels of accuracy on this task in contrast to what was expected. One explanation furthered for this result was that those with higher AQ-10 scores may have had more difficulties maintaining the overall stimulus context in memory. Such work adds greatly to knowledge of the nature of the individual differences that can affect performance on this particular task.

An investigation of the mechanisms underlying the link between abstract reasoning and intrusive memories: A trauma analogue study

Potentially traumatic events elicit intrusive memories to which some individuals are more vulnerable than others. Lower abstract reasoning capacity has been related to more intrusive memories. A more perceptual processing style when encoding the event may mediate this link. Another potential mechanism is lower attentional control, resulting in greater attentional bias toward trauma-related content. We examined both of these possibilities using a trauma-analogue paradigm. One hundred and twenty participants completed abstract reasoning tasks. Then, 90 participants watched a negative video, and 30 participants watched a neutral video. The level of perceptual processing (P1) and attentional bias (RT) towards trauma-related stimuli were measured with a pictorial Stroop task while recording EEG. Intrusive memories were recorded for 5 days. Abstract reasoning was not associated with intrusive memories. However, lower abstract reasoning tended to be associated with more perceptual processing (greater P1 amplitude) following the negative video. More perceptual processing also tended to be related to more intrusive memories for younger participants. A more pronounced attentional bias was related to more intrusive memories, but only for women. Unexpectedly, also for women, better verbal reasoning was linked to a more pronounced attentional bias. Results are compared to existing studies and future implications are discussed.

The production of false recognition and the associated state of consciousness following encoding in a naturalistic context in aging

Using virtual reality, we implemented a naturalistic variant of the DRM paradigm in young and older adults to evaluate false recall and false recognition. We distinguished false recognition related to the highest semantic association (the critical lures), semantic similarity (i.e. items that belong to the same semantic category), and perceptual similarity (i.e. items that are similar, but not identical in terms of shape or color). The data revealed that younger adults recalled and recognized more correct elements than older adults did while the older adults intruded more critical items than younger adults. Both age groups produced false recognition related to the critical items, followed by perceptually and then semantically related items. False recognitions were highly recollective as they were mainly associated with a sense of remembering, even more so in older adults than in young adults. The decline of executive functions and working memory predicted age-related increases in false memories.

Validity, reliability, and psychometric properties of a computerized, cognitive assessment test (Cognivue®)

BACKGROUND

Cognitive issues such as Alzheimer’s disease and other dementias confer a substantial negative impact. Problems relating to sensitivity, subjectivity, and inherent bias can limit the usefulness of many traditional methods of assessing cognitive impairment.

AIM

To determine cut-off scores for classification of cognitive impairment, and assess Cognivue^® safety and efficacy in a large validation study.

METHODS

Adults (age 55-95 years) at risk for age-related cognitive decline or dementia were invited via posters and email to participate in two cohort studies conducted at various outpatient clinics and assisted- and independent-living facilities. In the cut-off score determination study (n = 92), optimization analyses by positive percent agreement (PPA) and negative percent agreement (NPA), and by accuracy and error bias were conducted. In the clinical validation study (n = 401), regression, rank linear regression, and factor analyses were conducted. Participants in the clinical validation study also completed other neuropsychological tests.

RESULTS

For the cut-off score determination study, 92 participants completed St. Louis University Mental Status (SLUMS, reference standard) and Cognivue^® tests. Analyses showed that SLUMS cut-off scores of < 21 (impairment) and > 26 (no impairment) corresponded to Cognivue^® scores of 54.5 (NPA = 0.92; PPA = 0.64) and 78.5 (NPA = 0.5; PPA = 0.79), respectively. Therefore, conservatively, Cognivue^® scores of 55-64 corresponded to impairment, and 74-79 to no impairment. For the clinical validation study, 401 participants completed ≥ 1 testing session, and 358 completed 2 sessions 1-2 wk apart. Cognivue^® classification scores were validated, demonstrating good agreement with SLUMS scores (weighted κ 0.57; 95%CI: 0.50-0.63). Reliability analyses showed similar scores across repeated testing for Cognivue^® (R² = 0.81; r = 0.90) and SLUMS (R² = 0.67; r = 0.82). Psychometric validity of Cognivue^® was demonstrated vs. traditional neuropsychological tests. Scores were most closely correlated with measures of verbal processing, manual dexterity/speed, visual contrast sensitivity, visuospatial/executive function, and speed/sequencing.

CONCLUSION

Cognivue^® scores ≤ 50 avoid misclassification of impairment, and scores ≥ 75 avoid misclassification of unimpairment. The validation study demonstrates good agreement between Cognivue^® and SLUMS; superior reliability; and good psychometric validity.

Alterations in electrophysiological indices of perceptual processing and discrimination are associated with co-occurring emotional and behavioural problems in adolescents with autism spectrum disorder

Background

Many young people with autism spectrum disorder (ASD) experience emotional and behavioural problems. However, the causes of these co-occurring difficulties are not well understood. Perceptual processing atypicalities are also often reported in individuals with ASD, but how these relate to co-occurring emotional and behavioural problems remains unclear, and few studies have used objective measurement of perceptual processing.

Methods

Event-related potentials (ERPs) were recorded in response to both standard and deviant stimuli (which varied in pitch) in an auditory oddball paradigm in adolescents (mean age of 13.56 years, SD = 1.12, range = 11.40–15.70) with ASD (n = 43) with a wide range of IQ (mean IQ of 84.14, SD = 24.24, range 27–129). Response to deviant as compared to standard stimuli (as indexed by the mismatch negativity (MMN)) and response to repeated presentations of standard stimuli (habituation) were measured. Multivariate regression tested the association between neural indices of perceptual processing and co-occurring emotional and behavioural problems.

Results

Greater sensitivity to changes in pitch in incoming auditory information (discrimination), as indexed by increased MMN amplitude, was associated with higher levels of parent-rated behaviour problems. MMN amplitude also showed a trend positive correlation with parent-rated sensory hyper-sensitivity. Conversely, greater habituation at the later N2 component was associated with higher levels of emotional problems. Upon more detailed analyses, this appeared to be driven by a selectively greater ERP response to the first (but not the second or third) standard stimuli that followed deviant stimuli. A similar pattern of association was found with other measures of anxiety. All results remained in covariation analyses controlling for age, sex and IQ, although the association between MMN amplitude and behaviour problems became non-significant when controlling for ASD severity.

Conclusions

Findings suggest that alterations in mechanisms of perceptual processing and discrimination may be important for understanding co-occurring emotional and behavioural problems in young people with ASD.

Electronic supplementary material

The online version of this article (10.1186/s13229-018-0236-2) contains supplementary material, which is available to authorized users.

Emotional content modulates response inhibition and perceptual processing

In this study, event-related potentials were used to investigate the effect of emotion on response inhibition. Participants performed an emotional go/no-go task that required responses to human faces associated with a "go" valence (i.e., emotional, neutral) and response inhibition to human faces associated with a "no-go" valence. Emotional content impaired response inhibition, as evidenced by decreased response accuracy and N2 amplitudes in no-go trials. More importantly, emotional expressions elicited larger N170 amplitudes than neutral expressions, and this effect was larger in no-go than in go trials, indicating that the perceptual processing of emotional expression had priority in inhibitory trials. In no-go trials, correlation analysis showed that increased N170 amplitudes were associated with decreased N2 amplitudes. Taken together, our findings suggest that emotional content impairs response inhibition due to the prioritization of emotional content processing.