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Modulation of Emotional Category Induced by Temporal Factors in Emotion Recognition.

Maeshima H, Yamashita Y, Fujimura T, Okada M, Okanoya K - PLoS ONE (2015)

Bottom Line: CP is considered as the result of the integration of the top-down processing including background knowledge and verbal labeling and the bottom-up processing such as physical characteristics of the sensory signal.The results demonstrated that the emotionally ambiguous stimuli are categorized more distinctively with the extension of delay length, not of stimulus duration.These findings suggest that paying more attention to temporal factors in CP could be useful for further study of the mechanisms underlying CP.

View Article: PubMed Central - PubMed

Affiliation: Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan; JST, ERATO, Okanoya Emotional Information Project, Wako, Saitama, Japan.

ABSTRACT
Categorical perception (CP), the perceptual experience whereby continuous sensory phenomena are perceived as distinct and separate percepts, is one of the most characteristic features of information processing in human cognition. CP is considered as the result of the integration of the top-down processing including background knowledge and verbal labeling and the bottom-up processing such as physical characteristics of the sensory signal. However, the underlying mechanisms governing the integration remain unclear. To address this issue, we focused on the temporal characteristics of CP of facial expression. In the current study, we investigated the contributions of temporal factors in CP processes, using facial expression recognition tasks as an example of CP. Participants completed an identification task and a discrimination task, well-established tasks for evaluating CP of facial expressions, with variable temporal parameters, that is, duration of stimulus presentation and delay time (interval between stimulus and response). The results demonstrated that the emotionally ambiguous stimuli are categorized more distinctively with the extension of delay length, not of stimulus duration. In contrast, the category boundary for facial expressions shifted toward "happy" with extention in stimulus duration, not in delay length. This dissociation between the impact of stimulus duration and delay suggests that there are two processes contributing to CP of facial emotion; one process may reflect the internal processing associated with the length of the delay period including verbal labeling of the stimuli, and the other process may reflect the temporal summation of stimulus inputs, associated with stimulus duration. These findings suggest that paying more attention to temporal factors in CP could be useful for further study of the mechanisms underlying CP.

No MeSH data available.


Related in: MedlinePlus

Trial sequence for the (a) identification and (b) discrimination tasks.Each task began with a fixation point (450 ms), followed by a blank screen (300 ms), a target face (50/200/750 ms), a white-noise mask (150 ms), blank screen (50/750 ms), and (a) two emotion words (identification task) or (b) two faces (discrimination task).
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pone.0131636.g002: Trial sequence for the (a) identification and (b) discrimination tasks.Each task began with a fixation point (450 ms), followed by a blank screen (300 ms), a target face (50/200/750 ms), a white-noise mask (150 ms), blank screen (50/750 ms), and (a) two emotion words (identification task) or (b) two faces (discrimination task).

Mentions: In the identification task, participants were required to identify the facial expression of a target stimulus as quickly as possible by choosing between the words “happy” and “fearful.” For example, in a trial, participants may be asked to judge whether the face-2 stimulus (87.5% happy, 12.5% fearful) is happy or fearful by pressing a button. Fig 2a illustrates the procedure for the identification task. Each trial began with a fixation point (450 ms), followed by a blank screen (300 ms), the target face image (50, 200, or 750 ms), and a white noise masking image (150 ms). After a blank interval (50 or 750 ms), two emotion words (happy and fearful) were presented until the participant responded by pressing one of the assigned buttons. The assignment of buttons was right index finger (left button) and right middle finger (right button). Therefore, the period between target face presentation and the two emotion words (participants’ response) was 200 or 900 ms (including masking), which we refer to as the 200 and 900 ms delay conditions, respectively.


Modulation of Emotional Category Induced by Temporal Factors in Emotion Recognition.

Maeshima H, Yamashita Y, Fujimura T, Okada M, Okanoya K - PLoS ONE (2015)

Trial sequence for the (a) identification and (b) discrimination tasks.Each task began with a fixation point (450 ms), followed by a blank screen (300 ms), a target face (50/200/750 ms), a white-noise mask (150 ms), blank screen (50/750 ms), and (a) two emotion words (identification task) or (b) two faces (discrimination task).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4521787&req=5

pone.0131636.g002: Trial sequence for the (a) identification and (b) discrimination tasks.Each task began with a fixation point (450 ms), followed by a blank screen (300 ms), a target face (50/200/750 ms), a white-noise mask (150 ms), blank screen (50/750 ms), and (a) two emotion words (identification task) or (b) two faces (discrimination task).
Mentions: In the identification task, participants were required to identify the facial expression of a target stimulus as quickly as possible by choosing between the words “happy” and “fearful.” For example, in a trial, participants may be asked to judge whether the face-2 stimulus (87.5% happy, 12.5% fearful) is happy or fearful by pressing a button. Fig 2a illustrates the procedure for the identification task. Each trial began with a fixation point (450 ms), followed by a blank screen (300 ms), the target face image (50, 200, or 750 ms), and a white noise masking image (150 ms). After a blank interval (50 or 750 ms), two emotion words (happy and fearful) were presented until the participant responded by pressing one of the assigned buttons. The assignment of buttons was right index finger (left button) and right middle finger (right button). Therefore, the period between target face presentation and the two emotion words (participants’ response) was 200 or 900 ms (including masking), which we refer to as the 200 and 900 ms delay conditions, respectively.

Bottom Line: CP is considered as the result of the integration of the top-down processing including background knowledge and verbal labeling and the bottom-up processing such as physical characteristics of the sensory signal.The results demonstrated that the emotionally ambiguous stimuli are categorized more distinctively with the extension of delay length, not of stimulus duration.These findings suggest that paying more attention to temporal factors in CP could be useful for further study of the mechanisms underlying CP.

View Article: PubMed Central - PubMed

Affiliation: Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan; JST, ERATO, Okanoya Emotional Information Project, Wako, Saitama, Japan.

ABSTRACT
Categorical perception (CP), the perceptual experience whereby continuous sensory phenomena are perceived as distinct and separate percepts, is one of the most characteristic features of information processing in human cognition. CP is considered as the result of the integration of the top-down processing including background knowledge and verbal labeling and the bottom-up processing such as physical characteristics of the sensory signal. However, the underlying mechanisms governing the integration remain unclear. To address this issue, we focused on the temporal characteristics of CP of facial expression. In the current study, we investigated the contributions of temporal factors in CP processes, using facial expression recognition tasks as an example of CP. Participants completed an identification task and a discrimination task, well-established tasks for evaluating CP of facial expressions, with variable temporal parameters, that is, duration of stimulus presentation and delay time (interval between stimulus and response). The results demonstrated that the emotionally ambiguous stimuli are categorized more distinctively with the extension of delay length, not of stimulus duration. In contrast, the category boundary for facial expressions shifted toward "happy" with extention in stimulus duration, not in delay length. This dissociation between the impact of stimulus duration and delay suggests that there are two processes contributing to CP of facial emotion; one process may reflect the internal processing associated with the length of the delay period including verbal labeling of the stimuli, and the other process may reflect the temporal summation of stimulus inputs, associated with stimulus duration. These findings suggest that paying more attention to temporal factors in CP could be useful for further study of the mechanisms underlying CP.

No MeSH data available.


Related in: MedlinePlus