Temporal experience in recovery from psychosis

Phenomenology and the Cognitive Sciences - During recovery from psychosis (diagnosed as schizophrenia) things must often be done slower than normally expected. The tempo of the socially shared...     

Temporal production and visuospatial processing

Current models of prospective timing hypothesize that estimated duration is influenced either by the attentional load or by the short-term memory requirements of a concurrent nontemporal task. In the present study, we addressed this issue with four dual-task experiments. In Exp. 1, the effect of memory load on both reaction time and temporal production was proportional to the number of items of a visuospatial pattern to hold in memory. In Exps. 2, 3, and 4, a temporal production task was combined with two visual search tasks involving either pre-attentive or attentional processing. Visual tasks interfered with temporal production: produced intervals were lengthened proportionally to the display size. In contrast, reaction times increased with display size only when a serial, effortful search was required. It appears that memory and perceptual set size, rather than nonspecific attentional or short-term memory load, can influence prospective timing.     

Temporal information processing and psychopathology.

Prior studies showed impaired temporal discrimination by schizophrenic and neurologic patients reflected in decreased information transmission. This report describes a study of 8 more carefully diagnosed schizophrenic patients, separating those with neurologic signs. Using temporal discrimination tasks involving two psychophysical methods, 8 schizophrenic patients with no organic signs did not differ from 17 nonpsychotic, nonorganic patients; and organic group (n = 5) transmitted less information than the other patient samples. It is suggested that prior results were a product of casual diagnosis that ignored organic factors; reduced efficiency of temporal processing is associated predominantly with neurologic impairment.     

Temporal processing within and across senses

This special issue on temporal processing within and across senses was the outcome of a two-day workshop that took place in Tübingen, Germany. The aim of the workshop and this special issue was to advance our knowledge on timing and the senses and to bring together two lines of research that have not yet interacted, those of synchrony and duration perception.     

Disintegration: A reconceptualization of psychosis proneness as a personality trait separate from the Big Five

A nine-facet hierarchical taxonomy of “Disintegration”, a trait-like disposition that causes variations in psychotic-like behavior, is proposed, along with the scales to assess it. Strong correlations were demonstrated in students (n = 466) between lower-level dimensions, independent of the assessment method. Disintegration lay beyond the Five-Factor Model (FFM) space. This finding was replicated across informant types (self, mother, and father), samples (students and a national representative sample, n = 1001), and units of analyses (facets and items). The most frequent approach to preserve the FFM taxonomy of both normal and non-normal personality variants – mapping psychotic-like phenomena onto the Openness domain – found little support in our data. Disintegration was normally distributed in the general population.     

Temporal processing in deaf signers

The auditory and visual modalities differ in their capacities for temporal analysis, and speech relies on more rapid temporal contrasts than does sign language. We examined whether congenitally deaf signers show enhanced or diminished capacities for processing rapidly varying visual signals in light of the differences in sensory and language experience of deaf and hearing individuals. Four experiments compared rapid temporal analysis in deaf signers and hearing subjects at three different levels: sensation, perception, and memory. Experiment 1 measured critical flicker frequency thresholds and Experiment 2, two-point thresholds to a flashing light. Experiments 3-4 investigated perception and memory for the temporal order of rapidly varying nonlinguistic visual forms. In contrast to certain previous studies, specifically those investigating the effects of short-term sensory deprivation, no significant differences between deaf and hearing subjects were found at any level. Deaf signers do not show diminished capacities for rapid temporal analysis, in comparison to hearing individuals. The data also suggest that the deficits in rapid temporal analysis reported previously for children with developmental language delay cannot be attributed to lack of experience with speech processing and production.     

Temporal uncertainty degrades perceptual processing

When participants are required to react to a stimulus, reaction times (RTs) are usually reduced when temporal uncertainty about stimulus occurrence is minimized. Contrary to the common assumption attributing this RT benefit solely to the speeding of motor processes, recent evidence suggests that temporal uncertainty might rather influence premotoric processing levels. We employed a backward-masking procedure to further confine the locus of the temporal uncertainty effect. Participants performed a discrimination task and indicated whether a spatial gap within a square was on the right or the left side. In addition to the shorter RTs, visual discrimination accuracy was improved when temporal uncertainty was low. This result demonstrates that temporal uncertainty influences stimulus processing at a perceptual level.     

Temporal processing dysfunction in schizophrenia

Schizophrenia may be associated with a fundamental disturbance in the temporal coordination of information processing in the brain, leading to classic symptoms of schizophrenia such as thought disorder and disorganized and contextually inappropriate behavior. Despite the growing interest and centrality of time-dependent conceptualizations of the pathophysiology of schizophrenia, there remains a paucity of research directly examining overt timing performance in the disorder. Accordingly, the present study investigated timing in schizophrenia using a well-established task of time perception. Twenty-three individuals with schizophrenia and 22 non-psychiatric control participants completed a temporal bisection task, which required participants to make temporal judgments about auditory and visually presented durations ranging from 300 to 600 ms. Both schizophrenia and control groups displayed greater visual compared to auditory timing variability, with no difference between groups in the visual modality. However, individuals with schizophrenia exhibited less temporal precision than controls in the perception of auditory durations. These findings correlated with parameter estimates obtained from a quantitative model of time estimation, and provide evidence of a fundamental deficit in temporal auditory precision in schizophrenia.     

Self-concept and delinquency proneness

Contrary to the theory of the homeostatic model of self-concept, i.e., the expectancy that engaging in anti-social or pro-social behavior results typically in shifts in the self-concept (Graf, 1968; Deitz, 1970 shifts did not occur. Subjects, 12- 14-year-old boys enrolled in junior high school, delinquent prone (DP) and non-delinquent prone bright (NDPB), reacted to manipulation by engaging in reparative behavior as indicated via an aggression module in a fashion generally expected but the expected shift from chronic self-images did not occur. Both DP and NDPB viewed themselves similarly on self concept. The authors postulated that if shifts would occur for the delinquent prone it would be after they left school with its accompanying identification with a sub-culture outside the school setting.     

Fantasy proneness and psychopathology

Fantasy prone persons ("fantasizers") selected from "normal" populations report experiences associated with psychopathology in clinical populations (e.g., fantasies that reach hallucinatory proportions, difficulty discriminating reality from fantasy). In Study 1, we administered objective (MMPI) and projective (Rorschach) measures to high fantasy prone individuals (upper 4% of college population), medium fantasy prone individuals (middle range), and nonfantasizers (lowest 4%). Subjects who were fantasizers appeared to use fantasy for defensive or adaptive purposes compared with others and produced 8/9 modal code types on the MMPI. On the basis of the MMPI findings, a subset of fantasizers could be described as exhibiting a significant degree of psychopathology. In Study 2, a second sample of fantasy prone individuals could not be distinguished from comparison groups in contacts with professionals for help with psychological problems, use of psychotropic medication, or number of close friendships. Although fantasizers perceived themselves as less well adjusted than comparison subjects and reported greater difficulty in distinguishing fantasy from reality, most fantasizers rated their psychological functioning as adequate and above and did not differ from less fantasy prone subjects in ratings of positivity of self-concept. As demonstrated in Study 1, a subset of fantasizers did appear to be more pathological than other subjects were, with three fantasizers reporting a history of psychiatric hospitalizations. It is estimated that between 10 and 20% of fantasizers exhibit significant signs of maladjustment/psychopathology; however, as a rule, fantasy proneness does not appear to be antecedent to severe manifestations of psychopathology.     

Temporal interval production and processing in working memory

Short-term memory or working memory has been proposed as a cognitive structure contributing to time estimation. Thus, in a previous experiment, retrieving a stored item during a temporalinterval production lengthened the interval in proportion to the number of items in the memory set. In the present study, this issue was analyzed further by testing whether the proportional lengthening is induced by the load itself (i.e., the number of items) or by comparing the probe with memorized items. In a first experiment, a memory set was maintained during a temporal production, and the comparison of the probe with memorized items was postponed until the end of time production. Varying the number of items in the memory set had no effect on temporal intervals produced during its retention, suggesting that mental comparison was the source of the lengthening of time intervals. In succeeding experiments, tasks requiring processing in working memory but involving no memory load were combined with temporal production. In Experiment 2, increasing the number of syllables in a rhyme-judgment task proportionally lengthened temporal intervals that were produced simultaneously. In Experiment 3, increasing the amount of mental rotation in a task involving visuospatial processing also lengthened simultaneous temporal production. This interference between processing in working memory and time estimation suggests that working memory, defined as a work space for active processing of current information, contributes to time estimation.     

Aberrant semantic and affective processing in people at risk for psychosis

Semantic and affective processing were examined in people at risk for psychosis. The participants were 3 groups of college students: 41 people with elevated Perceptual Aberration and Magical Ideation (PerMag) scores, 18 people with elevated Social Anhedonia (SocAnh) scores, and 100 control participants. Participants completed a single-word, continuous presentation pronunciation task that included semantically related words, affectively valenced words, and semantically unrelated and affectively neutral words. PerMag participants exhibited increased semantic priming and increased sensitivity to affectively valenced primes. SocAnh participants had increased sensitivity to affectively valenced targets.     

Temporal and spatial Characteristics of preattentive and attentive processing

Abstract

In the present experiment, subjects searched multielement displays for a colour singleton. With a variable display-to-onset SOA, on some trials an abrupt onset was presented at three possible distances from the target location. The interference effect caused by the abrupt onset as a function of SOA and its relative position revealed the distinctive characteristics of preattentive and attentive processing. During preattentive parallel processing (processing occurring within the first 100 msec), any abrupt onset that occurred within the visual field captured attention. During attentive processing (processing occurring after 100 msec), however, focused attention prevented the abrupt onset from capturing attention. The finding that abrupt onsets interfere with selective search for a colour singleton provides additional evidence for the theory of inadequate top-down control at the level of preattentive processing.     

Temporal processing capabilities in repetition conduction aphasia

This study investigates the temporal resolution capacities of the central-auditory system in a subject (NP) suffering from repetition conduction aphasia. More specifically, the patient was asked to detect brief gaps between two stretches of broadband noise (gap detection task) and to evaluate the duration of two biphasic (WN-3) continuous noise elements, starting with white noise (WN) followed by 3 kHz bandpass-filtered noise (duration discrimination task). During the gap detection task, the two portions of each stimulus were either identical (“intra-channel condition”) or differed (“inter-channel condition”) in the spectral characteristics of the leading and trailing acoustic segments. NP did not exhibit any deficits in the intra-channel condition of the gap detection task, indicating intact auditory temporal resolution across intervals of 1–3 ms. By contrast, the inter-channel condition yielded increased threshold values. Based upon the “multiple-looks” model of central-auditory processing, this profile points at a defective integration window operating across a few tens of milliseconds – a temporal range associated with critical features of the acoustic speech signal such as voice onset time and formant transitions. Additionally, NP was found impaired during a duration discrimination task addressing longer integration windows (ca. 150 ms). Concerning speech, this latter time domain approximately corresponds to the duration of stationary segmental units such as fricatives and long vowels. On the basis of our results we suggest, that the patient’s auditory timing deficits in non-speech tasks may account, at least partially, for his impairments in speech processing.     

Fantasy proneness and counterfactual thinking

Counterfactual thinking (CFT; mentally simulating alternatives to reality) is central to learning and motivation. Two studies explored the relationship between CFT and fantasy proneness, a personality trait typified by excessive fantasies hard to distinguish from reality. In study1, participants completed a fictional diary entry which was used to measure spontaneous CFT and the Creative Experiences Questionnaire measure of fantasy proneness. Fantasy proneness was significantly correlated with the generation of counterfactual thoughts. Both CFT and fantasy proneness have been independently associated with low mood and study2 included a measure of negative emotional state (the Depression, Anxiety and Stress scale) in addition to the CEQ and CFT. Fantasy proneness and negative emotion both predicted CFT, but no interaction between them was observed. The results suggest that individuals high in fantasy proneness have a general tendency to think counterfactually.