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The duality of temporal encoding - the intrinsic and extrinsic representation of time.

Golan R, Zakay D - Front Psychol (2015)

Bottom Line: We found a gradual increase in neural activation associated with the gradual increase in temporal variance within category selective areas.We concluded that temporal features are integral to perception and are simultaneously represented within category selective regions and globally within dedicated regions.Our second conclusion, drown from our covert procedure, is that time encoding, at its basic level, is an automated process that does not require attention allocated toward the temporal features nor does it require dedicated resources.

View Article: PubMed Central - PubMed

Affiliation: School of Psychological Sciences, Tel Aviv University Tel Aviv, Israel.

ABSTRACT
While time is well acknowledged for having a fundamental part in our perception, questions on how it is represented are still matters of great debate. One of the main issues in question is whether time is represented intrinsically at the neural level, or is it represented within dedicated brain regions. We used an fMRI block design to test if we can impose covert encoding of temporal features of faces and natural scenes stimuli within category selective neural populations by exposing subjects to four types of temporal variance, ranging from 0% up to 50% variance. We found a gradual increase in neural activation associated with the gradual increase in temporal variance within category selective areas. A second level analysis showed the same pattern of activations within known brain regions associated with time representation, such as the Cerebellum, the Caudate, and the Thalamus. We concluded that temporal features are integral to perception and are simultaneously represented within category selective regions and globally within dedicated regions. Our second conclusion, drown from our covert procedure, is that time encoding, at its basic level, is an automated process that does not require attention allocated toward the temporal features nor does it require dedicated resources.

No MeSH data available.


(A) Grand average of the mean percent signal change in r/lCerebelum for all four conditions, showing a gradual increase in activation between conditions having variance in durations (i.e., 12.5, 25, and 50% variance) while the first condition with 0% variance showing a greater activation than the 12.5 and 25% variance conditions. (B) Grand average of FIR event time courses extracted from the r/lCerebellum (0, -63, -24). FIR event time courses peak at about 20-s after block onset; (C) Grand average of Fitted event time courses extracted from the rCerebellum.
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Figure 11: (A) Grand average of the mean percent signal change in r/lCerebelum for all four conditions, showing a gradual increase in activation between conditions having variance in durations (i.e., 12.5, 25, and 50% variance) while the first condition with 0% variance showing a greater activation than the 12.5 and 25% variance conditions. (B) Grand average of FIR event time courses extracted from the r/lCerebellum (0, -63, -24). FIR event time courses peak at about 20-s after block onset; (C) Grand average of Fitted event time courses extracted from the rCerebellum.

Mentions: Our findings suggest that there should be a distinction in the way time is represented between the Cerebellum and the Thalamus on the one hand, and the Basal-Ganglia on the other. As can be seen in Figure 10, time courses in the Basal Ganglia peaks at about 10-s after block onset. This finding is in line with our findings of the way time courses in category selective areas behave under this specific manipulation. However, time courses in the Cerebellum and the Thalamus differ significantly from that pattern. As can be seen (see Figures 9, 11, and 12), time courses in these regions peak at about 20-s after block onset (during fixation time) suggesting a secondary role in temporal encoding that may be based on temporal information processed in the Basal-Ganglia. These findings are supported by Rao et al. (2001), which presents an Event-Related fMRI experiment also showing that temporal processing in the Basal-Ganglia occurs relatively early with respect to the Cerebellum which they assigned to the Cerebellum involvement in the process of timing rather than to the encoding of explicit timing.


The duality of temporal encoding - the intrinsic and extrinsic representation of time.

Golan R, Zakay D - Front Psychol (2015)

(A) Grand average of the mean percent signal change in r/lCerebelum for all four conditions, showing a gradual increase in activation between conditions having variance in durations (i.e., 12.5, 25, and 50% variance) while the first condition with 0% variance showing a greater activation than the 12.5 and 25% variance conditions. (B) Grand average of FIR event time courses extracted from the r/lCerebellum (0, -63, -24). FIR event time courses peak at about 20-s after block onset; (C) Grand average of Fitted event time courses extracted from the rCerebellum.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4553368&req=5

Figure 11: (A) Grand average of the mean percent signal change in r/lCerebelum for all four conditions, showing a gradual increase in activation between conditions having variance in durations (i.e., 12.5, 25, and 50% variance) while the first condition with 0% variance showing a greater activation than the 12.5 and 25% variance conditions. (B) Grand average of FIR event time courses extracted from the r/lCerebellum (0, -63, -24). FIR event time courses peak at about 20-s after block onset; (C) Grand average of Fitted event time courses extracted from the rCerebellum.
Mentions: Our findings suggest that there should be a distinction in the way time is represented between the Cerebellum and the Thalamus on the one hand, and the Basal-Ganglia on the other. As can be seen in Figure 10, time courses in the Basal Ganglia peaks at about 10-s after block onset. This finding is in line with our findings of the way time courses in category selective areas behave under this specific manipulation. However, time courses in the Cerebellum and the Thalamus differ significantly from that pattern. As can be seen (see Figures 9, 11, and 12), time courses in these regions peak at about 20-s after block onset (during fixation time) suggesting a secondary role in temporal encoding that may be based on temporal information processed in the Basal-Ganglia. These findings are supported by Rao et al. (2001), which presents an Event-Related fMRI experiment also showing that temporal processing in the Basal-Ganglia occurs relatively early with respect to the Cerebellum which they assigned to the Cerebellum involvement in the process of timing rather than to the encoding of explicit timing.

Bottom Line: We found a gradual increase in neural activation associated with the gradual increase in temporal variance within category selective areas.We concluded that temporal features are integral to perception and are simultaneously represented within category selective regions and globally within dedicated regions.Our second conclusion, drown from our covert procedure, is that time encoding, at its basic level, is an automated process that does not require attention allocated toward the temporal features nor does it require dedicated resources.

View Article: PubMed Central - PubMed

Affiliation: School of Psychological Sciences, Tel Aviv University Tel Aviv, Israel.

ABSTRACT
While time is well acknowledged for having a fundamental part in our perception, questions on how it is represented are still matters of great debate. One of the main issues in question is whether time is represented intrinsically at the neural level, or is it represented within dedicated brain regions. We used an fMRI block design to test if we can impose covert encoding of temporal features of faces and natural scenes stimuli within category selective neural populations by exposing subjects to four types of temporal variance, ranging from 0% up to 50% variance. We found a gradual increase in neural activation associated with the gradual increase in temporal variance within category selective areas. A second level analysis showed the same pattern of activations within known brain regions associated with time representation, such as the Cerebellum, the Caudate, and the Thalamus. We concluded that temporal features are integral to perception and are simultaneously represented within category selective regions and globally within dedicated regions. Our second conclusion, drown from our covert procedure, is that time encoding, at its basic level, is an automated process that does not require attention allocated toward the temporal features nor does it require dedicated resources.

No MeSH data available.