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Cognition Jul 2016The fundamental goal of perception is to aid in the achievement of behavioral objectives. This requires extracting and communicating useful information from noisy and...
The fundamental goal of perception is to aid in the achievement of behavioral objectives. This requires extracting and communicating useful information from noisy and uncertain sensory signals. At the same time, given the complexity of sensory information and the limitations of biological information processing, it is necessary that some information must be lost or discarded in the act of perception. Under these circumstances, what constitutes an 'optimal' perceptual system? This paper describes the mathematical framework of rate-distortion theory as the optimal solution to the problem of minimizing the costs of perceptual error subject to strong constraints on the ability to communicate or transmit information. Rate-distortion theory offers a general and principled theoretical framework for developing computational-level models of human perception (Marr, 1982). Models developed in this framework are capable of producing quantitatively precise explanations for human perceptual performance, while yielding new insights regarding the nature and goals of perception. This paper demonstrates the application of rate-distortion theory to two benchmark domains where capacity limits are especially salient in human perception: discrete categorization of stimuli (also known as absolute identification) and visual working memory. A software package written for the R statistical programming language is described that aids in the development of models based on rate-distortion theory.
Topics: Bayes Theorem; Humans; Information Theory; Memory, Short-Term; Models, Psychological; Perception; Psychological Theory; Psychometrics; Visual Perception
PubMed: 27107330
DOI: 10.1016/j.cognition.2016.03.020 -
The Journal of the Acoustical Society... Apr 2018The equalization of headphones can force transducers to work in a non-linear condition, producing non-linear distortion. Depending on the headphone model and the...
The equalization of headphones can force transducers to work in a non-linear condition, producing non-linear distortion. Depending on the headphone model and the reproduction level, that distortion can be audible. In this study, headphones of diverse quality and price were compelled to emulate the same target frequency response and the non-linear distortion was measured. A Diagonal Volterra model was used to simulate the different headphones with and without distortion. A perceptual test was carried out to determine the level of reproduction above which non-linear distortion is perceived for each headphone model. High correlation has been found between the level of detected distortion and retail prices of headphones.
PubMed: 29716278
DOI: 10.1121/1.5031030 -
Proceedings. Biological Sciences Oct 2018Temporal processing is fundamental for an accurate synchronization between motor behaviour and sensory processing. Here, we investigate how motor timing during rhythmic...
Temporal processing is fundamental for an accurate synchronization between motor behaviour and sensory processing. Here, we investigate how motor timing during rhythmic tapping influences perception of visual time. Participants listen to a sequence of four auditory tones played at 1 Hz and continue the sequence (without auditory stimulation) by tapping four times with their finger. During finger tapping, they are presented with an empty visual interval and are asked to judge its length compared to a previously internalized interval of 150 ms. The visual temporal estimates show non-monotonic changes locked to the finger tapping: perceived time is maximally expanded at halftime between the two consecutive finger taps, and maximally compressed near tap onsets. Importantly, the temporal dynamics of the perceptual time distortion scales linearly with the timing of the motor tapping, with maximal expansion always being anchored to the centre of the inter-tap interval. These results reveal an intrinsic coupling between distortion of perceptual time and production of self-timed motor rhythms, suggesting the existence of a timing mechanism that keeps perception and action accurately synchronized.
Topics: Adult; Female; Humans; Male; Periodicity; Psychomotor Performance; Time Perception; Visual Perception; Young Adult
PubMed: 30282654
DOI: 10.1098/rspb.2018.1597 -
Schizophrenia Research Aug 2010Factor analytic studies have shown that in schizophrenia patients, disorganization (e.g., conceptual disorganization and bizarre behavior) is a separate dimension from... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Factor analytic studies have shown that in schizophrenia patients, disorganization (e.g., conceptual disorganization and bizarre behavior) is a separate dimension from other types of positive symptoms such as reality distortion (delusions and hallucinations). Although some studies have found that disorganization is more strongly linked to neurocognitive deficits and poor functional outcomes than reality distortion, the findings are not always consistent.
METHODS
A meta-analysis of 104 studies (combined n=8015) was conducted to determine the magnitude of the relationship between neurocognition and disorganization as compared to reality distortion. Additional analyses were conducted to determine whether the strength of these relationships differed depending on the neurocognitive domain under investigation.
RESULTS
The relationship between reality distortion and neurocognition was weak (r=-.04; p=.03) as compared to the moderate association between disorganization and neurocognition (r=-.23; p<.01). In each of the six neurocognitive domains that were examined, disorganization was more strongly related to neurocognition (r's range from -.20 to -.26) than to reality distortion (r's range from .01 to -.12).
CONCLUSIONS
The effect size of the relationship between neurocognition and disorganization was significantly larger than the effect size of the relationship between neurocognition and reality distortion. These results hold across several neurocognitive domains. These findings support a dimensional view of positive symptoms distinguishing disorganization from reality distortion.
Topics: Cognition Disorders; Female; Humans; Male; Neuropsychological Tests; Perceptual Distortion; Psychiatric Status Rating Scales; Reality Testing; Schizophrenia; Schizophrenic Psychology
PubMed: 20579855
DOI: 10.1016/j.schres.2010.05.033 -
Schizophrenia Bulletin May 2011Evidence from clinical patient populations indicates that affective dysregulation is strongly associated with reality distortion, suggesting that a process of...
Evidence from clinical patient populations indicates that affective dysregulation is strongly associated with reality distortion, suggesting that a process of misassignment of emotional salience may underlie this connection. To examine this in more detail without clinical confounds, affective regulation-reality distortion relationships, and their clinical relevance, were examined in a German prospective cohort community study. A cohort of 2524 adolescents and young adults aged 14-24 years at baseline was examined by experienced psychologists. Presence of psychotic experiences and (hypo)manic and depressive symptoms was assessed at 2 time points (3.5 and up to 10 years after baseline) using the Munich-Composite International Diagnostic Interview. Associations were tested between level of affective dysregulation on the one hand and incidence of psychotic experiences, persistence of these experiences, and psychotic Impairment on the other. Most psychotic experiences occurred in a context of affective dysregulation, and bidirectional dose-response was apparent with greater level of both affective dysregulation and psychotic experiences. Persistence of psychotic experiences was progressively more likely with greater level of (hypo)manic symptoms (odds ratio [OR] trend=1.51, P<.001) and depressive symptoms (OR trend=1.15, P=.012). Similarly, psychotic experiences of clinical relevance were progressively more likely to occur with greater level of affective dysregulation (depressive symptoms: OR trend=1.28, P=.002; (hypo)manic symptoms: OR trend=1.37, P=.036). Correlated genetic liabilities underlying affective and nonaffective psychotic syndromes may be expressed as correlated dimensions in the general population. Also, affective dysregulation may contribute causally to the persistence and clinical relevance of reality distortion, possibly by facilitating a mechanism of aberrant salience attribution.
Topics: Adolescent; Adolescent Development; Affective Symptoms; Bipolar Disorder; Depression; Female; Follow-Up Studies; Germany; Humans; Male; Perceptual Distortion; Prospective Studies; Reality Testing; Risk Factors; Young Adult
PubMed: 19793794
DOI: 10.1093/schbul/sbp101 -
Clinical Psychology Review Jan 2008Misperceiving a woman's platonic interest as sexual interest has been implicated in a sexual bargaining process that leads to sexual coercion. This paper provides a... (Comparative Study)
Comparative Study Review
Misperceiving a woman's platonic interest as sexual interest has been implicated in a sexual bargaining process that leads to sexual coercion. This paper provides a comprehensive review of sexual misperception, including gender differences in perception of women's sexual intent, the relationship between sexual coercion and misperception, and situational factors that increase the risk that sexual misperception will occur. Compared to women, men consistently perceive a greater degree of sexual intent in women's behavior. However, there is evidence to suggest that this gender effect may be driven largely by a sub-group of men who are particularly prone to perceive sexual intent in women's behavior, such as sexually coercive men and men who endorse sex-role stereotypes. Situational factors, such as alcohol use by the man or woman, provocative clothing, and dating behaviors (e.g., initiating the date or making eye contact), are all associated with increased estimates of women's sexual interest. We also critique the current measurement strategies and introduce a model of perception that more closely maps on to important theoretical questions in this area. A clearer understanding of sexual perception errors and the etiology of these errors may serve to guide sexual-assault prevention programs toward more effective strategies.
Topics: Alcohol Drinking; Coercion; Female; Gender Identity; Humans; Individuality; Intention; Interpersonal Relations; Male; Models, Psychological; Perceptual Distortion; Rape; Sex Factors; Sexual Behavior; Social Perception
PubMed: 17462798
DOI: 10.1016/j.cpr.2007.03.002 -
Scientific Reports Dec 2022Precisely estimating event timing is essential for survival, yet temporal distortions are ubiquitous in our daily sensory experience. Here, we tested whether the...
Precisely estimating event timing is essential for survival, yet temporal distortions are ubiquitous in our daily sensory experience. Here, we tested whether the relative position, duration, and distance in time of two sequentially-organized events-standard S, with constant duration, and comparison C, with duration varying trial-by-trial-are causal factors in generating temporal distortions. We found that temporal distortions emerge when the first event is shorter than the second event. Importantly, a significant interaction suggests that a longer inter-stimulus interval (ISI) helps to counteract such serial distortion effect only when the constant S is in the first position, but not if the unpredictable C is in the first position. These results imply the existence of a perceptual bias in perceiving ordered event durations, mechanistically contributing to distortion in time perception. We simulated our behavioral results with a Bayesian model and replicated the finding that participants disproportionately expand first-position dynamic (unpredictable) short events. Our results clarify the mechanisms generating time distortions by identifying a hitherto unknown duration-dependent encoding inefficiency in human serial temporal perception, something akin to a strong prior that can be overridden for highly predictable sensory events but unfolds for unpredictable ones.
Topics: Humans; Bayes Theorem; Perception
PubMed: 36473982
DOI: 10.1038/s41598-022-25573-9 -
Schizophrenia Bulletin Nov 2009Persons with schizophrenia experience subjective sensory anomalies and objective deficits on assessment of sensory function. Such deficits could be produced by abnormal... (Review)
Review
Persons with schizophrenia experience subjective sensory anomalies and objective deficits on assessment of sensory function. Such deficits could be produced by abnormal signaling in the sensory pathways and sensory cortex or later stage disturbances in cognitive processing of such inputs. Steady state responses (SSRs) provide a noninvasive method to test the integrity of sensory pathways and oscillatory responses in schizophrenia with minimal task demands. SSRs are electrophysiological responses entrained to the frequency and phase of a periodic stimulus. Patients with schizophrenia exhibit pronounced auditory SSR deficits within the gamma frequency range (35-50 Hz) in response to click trains and amplitude-modulated tones. Visual SSR deficits are also observed, most prominently in the alpha and beta frequency ranges (7-30 Hz) in response to high-contrast, high-luminance stimuli. Visual SSR studies that have used the psychophysical properties of a stimulus to target specific visual pathways predominantly report magnocellular-based deficits in those with schizophrenia. Disruption of both auditory and visual SSRs in schizophrenia are consistent with neuropathological and magnetic resonance imaging evidence of anatomic abnormalities affecting the auditory and visual cortices. Computational models suggest that auditory SSR abnormalities at gamma frequencies could be secondary to gamma-aminobutyric acid-mediated or N-methyl-D-aspartic acid dysregulation. The pathophysiological process in schizophrenia encompasses sensory processing that probably contributes to alterations in subsequent encoding and cognitive processing. The developmental evolution of these abnormalities remains to be characterized.
Topics: Animals; Attention; Auditory Pathways; Brain; Brain Mapping; Cognition Disorders; Electroencephalography; Evoked Potentials; Humans; Interneurons; Neural Networks, Computer; Perceptual Disorders; Perceptual Distortion; Rats; Rats, Sprague-Dawley; Reaction Time; Receptors, GABA; Receptors, N-Methyl-D-Aspartate; Schizophrenia; Schizophrenic Psychology; Somatosensory Cortex; Visual Pathways
PubMed: 19726534
DOI: 10.1093/schbul/sbp091 -
Vision Research Dec 2018Face and visual word recognition are two key forms of expert visual processing. In the domain of object recognition, it has been suggested that expert processing is...
Face and visual word recognition are two key forms of expert visual processing. In the domain of object recognition, it has been suggested that expert processing is characterized by the use of different mechanisms from the ones involved in general object recognition. It has been suggested that one traditional marker of expert processing is the inversion effect. To investigate whether face and word recognition differ from general object recognition, we compared the effect of inversion on the perceptual efficiency of face and visual word recognition as well as on the recognition of a third, non-expert object category, houses. From the comparison of identification contrast thresholds to an ideal observer, we derived the efficiency and equivalent input noise of stimulus processing in both upright and inverted orientations. While efficiency reflects the efficacy in sampling the available information, equivalent input noise is associated with the degradation of the stimulus signal within the visual system. We hypothesized that large inversion effects for efficiency and/or equivalent input noise should characterize expert high-level processes, and asked whether this would be true for both faces and words, but not houses. However, we found that while face recognition efficiency was profoundly reduced by inversion, the efficiency of word and house recognition was minimally influenced by the orientation manipulation. Inversion did not affect equivalent input noise. These results suggest that even though faces and words are both considered expert processes, only the efficiency of the mechanism involved in face recognition is sensitive to orientation.
Topics: Adult; Facial Recognition; Female; Housing; Humans; Male; Orientation; Pattern Recognition, Visual; Perceptual Distortion; Reading; Young Adult
PubMed: 30391292
DOI: 10.1016/j.visres.2018.10.008 -
Proceedings. Biological Sciences Oct 2017Ever since the days of René Descartes, in the seventeenth century, the search for the relationship between subjective perception and neural activity has been an ongoing...
Ever since the days of René Descartes, in the seventeenth century, the search for the relationship between subjective perception and neural activity has been an ongoing challenge. In neuroscience, an approach to the problem via the visual system has produced a paradigm using perceptual suppression, changing with time. Cortical areas in which the neural activity was modulated in temporal correlation with this percept could be traced. Although these areas may lead directly to perception, such temporal correlation of neural activity does not suffice as ultimate proof that they actually do so. In this article, I will use a different method to show that, for the perception of our own retina, any brain area leading directly to this perception also needs to represent the retina without distortion. Furthermore, I will demonstrate that the phenomenon of size constancy must be realized in this area.
Topics: Brain; Humans; Photic Stimulation; Retina; Visual Perception
PubMed: 29070728
DOI: 10.1098/rspb.2017.1904