Infant-adult vocal interaction dynamics depend on infant vocal type,child-directedness of adult speech,and timeframe

This study explored the temporal contingencies between infant and adult vocalizations as a function of the type of infant vocalization, whether adult caregivers’ vocalizations were infant-directed or other-directed, and the timescale of analysis. We analyzed excerpts taken from day-long home audio recordings that were collected from nineteen 12- to 13-month-old American infants and their caregivers using the LENA system. Three 5-minute sections having high child vocalization rates were identified within each recording and coded by trained researchers. Infant and adult vocalizations were sequenced and defined as contingent if they occurred within 1 s, 2 s, or 5 s of each other. When using 1 s or 2 s definitions of temporal adjacency, infant vocalizations generally predicted subsequent infant-directed adult vocalizations. A reflexive vocalization (i.e. a cry or a laugh) was the strongest predictor. Likewise, within 1–2 s timeframes, infant-directed adult speech generally predicted infant vocalizations with reflexive vocalizations being particularly predictive. Infant vocalizations predicted fewer subsequent other-directed adult vocalizations and were less likely following other-directed adult vocalizations when considering up to 5 s lags. This suggests an understudied communicative role for infants of non-infant-directed adult speech. These results demonstrate the importance of timescale in studying infant-adult interactions, support the communicative significance of reflexive infant vocalizations and other-directed adult speech in addition to more commonly studied vocalization types, and highlight the challenges of determining direction(s) of influence when using only two-event sequences.     

The role of the magnocellular and parvocellular pathways in the attentional blink

The attentional blink refers to the transient impairment in perceiving the 2nd of two targets presented in close temporal proximity in a rapid serial visual presentation (RSVP) stream. The purpose of this study was to examine the effect on human attentional-blink performance of disrupting the function of the magnocellular pathway--a major visual-processing pathway specialized in temporal segregation. The study was motivated by recent theories that relate the attentional blink to the limited temporal resolution of attentional responses, and by a number of poorly understood empirical findings, including the effects on the attentional blink of luminance adaptation and distraction. The attentional blink was assessed for stimuli on a red background (Experiment 1), stimuli on an equiluminant background (Experiment 2), and following flicker or motion adaptation (Experiment 3), three psychophysical manipulations known to disrupt magnocellular function. Contrary to our expectations, the attentional blink was not affected by these manipulations, suggesting no specific relationship between the attentional blink and magnocellular and/or parvocellular processing.     

Does attention impair temporal discrimination? Examining non-attentional accounts

Recently, Yeshurun and Levy (Psychol Sci 14:225-231, 2003) have provided evidence for the notion that visual attention impairs the temporal resolution of the visual system. Specifically, the detection of a temporal gap within a visual stimulus was impaired when a cue directed attention towards the spatial location of the stimulus. As this negative cueing effect is important to constrain theories about visual attention, we further investigated this novel effect and assessed whether it truly reflects an attentional effect. Experiment 1 examines whether the negative cueing effect is due to local temporal interference, and Experiments 2 and 3 investigate whether it reflects a luminance confound. The complete pattern of results argues against these alternatives and thus further strengthens the conclusion of Yeshurun and Levy (Psychol Sci 14: 225-231, 2003).     

PTSD青少年对威胁图片注意偏向的时程特点及习惯化倾向

探讨创伤后应激障碍(post-traumatic stress disorder,PTSD)青少年(n=20)与创伤控制组(n=20)对威胁图片注意偏向的时间进程特点以及习惯化倾向.在线索提示任务中,图片的呈现时间为100ms、500ms和1250ms.研究表明:(1)在时间进程上,当图片呈现100ms时,创伤控制组对地震图存在注意警觉;当呈现时间为500ms时,两组被试对负性图和地震图存在注意回避;当呈现时间为1250ms时,PTSD组对负性图仍存在注意回避、对地震图的注意偏向消失,创伤控制组对负性图和地震图的注意偏向均消失.(2)在习惯化倾向上,当第六次呈现威胁图片时,PTSD组对负性图和地震图的注意偏向消失,而创伤控制组对负性图和地震图的注意回避仍未消失.     

On emotional innumeracy: Predicted and actual affective responses to grand-scale tragedies

The present research demonstrates that people overestimate the intensity of their emotional responses to grand-scale tragedies. Participants predicted that they would feel significantly worse if thousands of people were killed in a disaster than if only a few people were killed, and yet they exhibited an “emotional flatline,” feeling equally sad regardless of the number of people killed. This unforeseeable emotional flatline was demonstrated in response to deaths stemming from human violence and natural disasters, both close to home and far away (including hurricanes in the United States, a forest fire in Spain, and the Iraq War). Participants’ actual emotional responses were calibrated with fatalities only when abstract death tolls were translated into concrete images. We argue that affective forecasts and emotional experiences may arise from separate systems, leading to reliable forecasting errors, as well as influencing subsequent judgments.     

The mechanism underlying inhibition of saccadic return

Human observers take longer to re-direct gaze to a previously fixated location. Although there has been some exploration of the characteristics of inhibition of saccadic return (ISR), the exact mechanisms by which ISR operates are currently unknown. In the framework of accumulation models of response times, in which evidence is integrated over time to a response threshold, ISR could reflect a reduction in the rate of accumulation for saccades to return locations or an increase in the effective criterion for response. In two experiments, participants generated sequences of three saccades, in response to a peripheral or a central cue. ISR occurred across these manipulations: saccade latency was consistently increased for movements to the immediately previously fixated location. Latency distributions from individual observers were fit with a Linear Ballistic Accumulator model. ISR was best accounted for as a change in the accumulation rate. We suggest this parameter represents the overall desirability of a particular course of action, the evidence for which may be derived from a variety of sensory and non-sensory sources.     

The influence of temporal resolution power and working memory capacity on psychometric intelligence

According to the temporal resolution power (TRP) hypothesis, higher TRP as reflected by better performance on psychophysical timing tasks accounts for faster speed of information processing and increased efficiency of information processing leading to better performance on tests of psychometric intelligence. An alternative explanation of individual differences in psychometric intelligence highlights individual differences in working memory (WM) capacity which has been found to be closely associated with psychometric intelligence. A latent variable approach was applied on the data of 200 participants ranging in age from 18 to 30 years and spanning a large range of levels of psychometric intelligence. Functional relationships were examined among TRP, WM capacity, as well as reasoning and speed of processing as two important aspects of psychometric intelligence. As predicted by the TRP hypothesis, the relation between TRP and psychometric intelligence was mediated by WM capacity supporting the view that higher TRP leads to better coordinated mental operations which, in turn, result in higher psychometric intelligence. The results are discussed against the background that WM capacity and psychometric reasoning are hardly dissociable from each other and that the specific factors limiting WM capacity and accounting for the mediation effect need to be identified in future research.     

Contributions of volumetrics of the hippocampus and thalamus to verbal memory in temporal lobe epilepsy patients

Recent theories have posited that the hippocampus and thalamus serve distinct, yet related, roles in episodic memory. Whereas the hippocampus has been implicated in long-term memory encoding and storage, the thalamus, as a whole, has been implicated in the selection of items for subsequent encoding and the use of retrieval strategies. However, dissociating the memory impairment that occurs following thalamic injury as distinguished from that following hippocampal injury has proven difficult. This study examined relationships between MRI volumetric measures of the hippocampus and thalamus and their contributions to prose and rote verbal memory functioning in 18 patients with intractable temporal lobe epilepsy (TLE). Results revealed that bilateral hippocampal and thalamic volume independently predicted delayed prose verbal memory functioning. However, bilateral hippocampal, but not thalamic, volume predicted delayed rote verbal memory functioning. Follow-up analyses indicated that bilateral thalamic volume independently predicted immediate prose, but not immediate rote, verbal recall, whereas bilateral hippocampal volume was not associated with any of these immediate memory measures. These findings underscore the cognitive significance of thalamic atrophy in chronic TLE, demonstrating that hippocampal and thalamic volume make quantitatively, and perhaps qualitatively, distinct contributions to episodic memory functioning in TLE patients. They are also consistent with theories proposing that the hippocampus supports long-term memory encoding and storage, whereas the thalamus is implicated in the executive aspects of episodic memory.     

Timing dysfunctions in schizophrenia as measured by a repetitive finger tapping task

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. Although a variety of behavioral studies have provided strong evidence for perceptual timing deficits in schizophrenia, no study to date has directly examined overt temporal performance in schizophrenia using a task that differentially engages perceptual and motor-based timing processes. The present study aimed to isolate perceptual and motor-based temporal performance in individuals diagnosed with schizophrenia using a repetitive finger-tapping task that has previously been shown to differentially engage brain regions associated with perceptual and motor-related timing behavior. Thirty-two individuals with schizophrenia and 31 non-psychiatric control participants completed the repetitive finger-tapping task, which required participants to first tap in time with computer-generated tones separated by a fixed intertone interval (tone-paced tapping), after which the tones were discontinued and participants were required to continue tapping at the established pace (self-paced tapping). Participants with schizophrenia displayed significantly faster tapping rates for both tone- and self-paced portions of the task compared to the non-psychiatric group. Individuals diagnosed with schizophrenia also displayed greater tapping variability during both tone- and self-paced portions of the task. The application of a mathematical timing model further indicated that group differences were primarily attributable to increased timing – as opposed to task implementation – difficulties in the schizophrenia group, which is noteworthy given the broad range of impairments typically associated with the disorder. These findings support the contention that schizophrenia is associated with a broad range of timing difficulties, including those associated with time perception as well as time production.     

Hindsight bias redefined: It’s about time

Four experiments introduced a new conceptual and methodological approach to hindsight bias, traditionally defined as the tendency to exaggerate the a priori predictability of outcomes after they become known. By examining likelihood estimates rooted to specific time points during an unfolding event sequence (videos and short text stories), judged both in foresight and hindsight, we conceptualized hindsight bias as a contrast between two “inevitability curves,” which plotted likelihood against time. Taking timing into account, we defined three new indicators of accuracy: linear accuracy (how well hindsight judgments capture the linear trend of foresight judgments over time), rate accuracy (how well hindsight judgments reflect the slope of foresight judgments over time), and temporal accuracy (how well hindsight judgments specify the overall timing of the full envelope of foresight judgments). Results demonstrated that hindsight judgments showed linear and rate accuracy, but were biased only in terms of lack of temporal accuracy. The oft-used catchphrase “knew it all along effect” was found to be a misnomer, in that participants were well aware in hindsight that their earlier foresight judgments reflected uncertainty. The current research therefore points to one way in which retrospective judgments can be considered biased, yet simultaneously suggests that considerable accuracy exists when people render such judgments.