Therehasbeenevidencefortheverybrief,temporalquantizationofperceptualexperienceatregularintervalsbelo w100msforseveraldecades.Webrieflydescribehowearlierstudiesledtotheconceptof“psychologicalmoment”ofbe tween50and60msduration.Accordingtohistoricaltheories,withinthepsychologicalmomentalleventswouldbepro cessedasco-temporal.Morerecently,alinkwithphysiologicalmechanismshasbeenproposed,accordingtowhichthe 50–60mspsychologicalmomentwouldbedefinedbytheupperlimitrequiredbyneuralmechanismstosynchronizeandthe rebyrepresentasnapshotofcurrentperceptualeventstructure.However,ourownexperimentaldevelopmentsalsoid entifyamorefine-scaled,serializedprocessstructurewithinthepsychologicalmoment.Ourdatasuggeststhatnot alleventsareprocessedasco-temporalwithinthepsychologicalmomentandinstead,someareprocessedsuccessivel y.Thisevidencequestionstheanalogrelationshipbetweensynchronizedprocessandsimultaneousexperienceandop ensdebateontheontologyandfunctionof“moments”inpsychologicalexperience.

Schizophrenia is associated with a series of visual perception impairments, which might impact on the patients’ every day life and be related to clinical symptoms. However, the heterogeneity of the visual disorders make it a challenge to understand both the mechanisms and the consequences of these impairments, i.e., the way patients experience the outer world. Based on earlier psychiatry literature, we argue that issues regarding time might shed a new light on the disorders observed in patients with schizophrenia.We will briefly (...) review the mechanisms involved in the sense of time continuity and clinical evidence that they are impaired in patients with schizophrenia.We will then summarize a recent experimental approach regarding the coding of time-event structure in time, namely the ability to discriminate between simultaneous and asynchronous events. The use of an original method of analysis allowed us to distinguish between explicit and implicit judgments of synchrony.We showed that for SOAs below 20ms neither patients nor controls fuse events in time. On the contrary subjects distinguish events at an implicit level even when judging them as synchronous. In addition, the implicit responses of patients and controls differ qualitatively. It is as if controls always put more weight on the last occurred event, whereas patients have a difficulty to follow events in time at an implicit level. In patients, there is a clear dissociation between results at short and large asynchronies, that suggest selective mechanisms for the implicit coding of time-event structure. These results might explain the disruption of the sense of time continuity in patients.We argue that this line of research might also help us to better understand the mechanisms of the visual impairments in patients and how they see their environment. (shrink)

Hoerl & McCormack's theory defines temporal behavior from an awareness of time, but lacks one critical element: the impact of “psychological presence” in the “moment now.” Central to experience of temporal non-stationarity: “Nowness” links future with past in the context of time flow. Does this differ between species? Evidence suggests not: Different temporal experiences between species requires greater critical evaluation.

Patient RP suffers a unilateral right homonymous quadrant anopia but demonstrates better than chance discrimination for stimuli presented in the blind field at temporal frequencies between 33 and 47 Hz . Examination of her reports of visual experience during blind-field discrimination suggests a more complex picture in which experiences particular to correct discrimination are not found at low-mid-gamma frequencies, but are significantly more likely than average at a lower frequency at which blindsight is not observed. We believe that visual experience (...) may serve to support blindsight if discrimination tasks are generally impaired at frequencies outside of the low-mid-gamma band. If this is so, although generally experienced as non-specific and unstructured light, the visual experience that accompanies discrimination performance must be based upon a neural representation which includes information on the visual features present in the stimulus. (shrink)

In a recent study, Becker and Elliott [Becker, C., & Elliott, M. A. . Flicker induced color and form: Interdependencies and relation to stimulation frequency and phase. Consciousness & Cognition, 15, 175–196] described the appearance of subjective experiences of color and form induced by stimulation with intermittent light. While there have been electroencephalographic studies of similar hallucinatory forms, brain activity accompanying the appearance of hallucinatory colors was never measured. Using a priming procedure where observers were required to indicate the presence (...) of one of eight target colors we compared electrophysiological correlates of hallucinatory color with brain states associated with other visual phenomena. Different target colors were accompanied by different patterns of EEG activation. However, in general, we found that the appearance of hallucinatory colors is preceded by a power decrease in the lower alpha band alongside an increase in gamma band frequencies. We argue that decreasing activity in the lower alpha band acts as a gating mechanism, inducing a switch in perception between different colors. The increasing gamma activation may correlate with the formation of a coherent conscious percept. (shrink)

In this commentary, the formation of “pre-iconic” visual-prime persistence is described in the context of prime-specific, independent-component activation at prefrontal and posterior EEG-recording sites. Although this activity subserves neural systems that are near identical to those described by Ruchkin and colleagues, we consider priming to be a dynamic process, identified with patterns of coherence and temporal structure of very high precision.

The purpose of this study was to investigate how the subjective impression of English speech would change when pause duration at punctuation marks was varied. Two listening experiments were performed in which written English speech segments were rated on a variety of evaluation items by both native-English speakers and non-native speakers. The ratings were then subjected to factor analysis. In the first experiment, the pauses in three segments were made into the same durations, from 0.075 to 4.8 s. Participants rated (...) the segments on 23 evaluation items on a rating scale from 1 to 10. A varimax rotation after PCA led to two factors that were related to speech style. These two factors could be interpreted as representing speech naturalness and speech rate. Speech segments with a pause duration of 0.6 s received the highest naturalness evaluation, while perceived speech rate decreased as the physical pause duration increased, without any changes in utterance segments. In the second experiment, a full-factorial design of pause durations within and between sentences, i.e., for commas and for periods, was implemented in two speech segments. The original speech segments and speech segments without any pauses were also included as control conditions. From ratings on 12 evaluation items, similar to Experiment 1, two factors representing speech naturalness and speech rate were obtained. The results showed again that the perceived speech rate decreased with an increase only in pause duration. As for speech naturalness, the highest evaluations occurred when pause durations were 0.6 s within sentences, and either 0.6 or 1.2 s between sentences. This recommends fixing all pause durations to 0.6 s as a practical way to train non-native speakers to make their spoken English appear more natural. (shrink)