Limits...
Cognitive modulation of local and callosal neural interactions in decision making.

Merchant H, Crowe DA, Fortes AF, Georgopoulos AP - Front Neurosci (2014)

Bottom Line: They were observed both within area 7a of the posterior parietal cortex and between symmetric 7a areas of the two hemispheres.Time lags for maximum interactions were longer for opposite- vs. same-hemisphere recordings, and lags for negative interactions were longer than for positive interactions in both recording sites.These findings underscore the involvement of dynamic neuronal interactions in cognitive processing within and across hemispheres.

View Article: PubMed Central - PubMed

Affiliation: Department of Behavioral and Cognitive Neurobiology, Instituto de Neurobiología, UNAM Querétaro, México.

ABSTRACT
Traditionally, the neurophysiological mechanisms of cognitive processing have been investigated at the single cell level. Here we show that the dynamic, millisecond-by-millisecond, interactions between neuronal events measured by local field potentials are modulated in an orderly fashion by key task variables of a space categorization task performed by monkeys. These interactions were stronger during periods of higher cognitive load and varied in sign (positive, negative). They were observed both within area 7a of the posterior parietal cortex and between symmetric 7a areas of the two hemispheres. Time lags for maximum interactions were longer for opposite- vs. same-hemisphere recordings, and lags for negative interactions were longer than for positive interactions in both recording sites. These findings underscore the involvement of dynamic neuronal interactions in cognitive processing within and across hemispheres. They also provide accurate estimates of lags in callosal interactions, very comparable to similar estimates of callosal conduction delays derived from neuroanatomical measurements (Caminiti et al., 2013).

No MeSH data available.


Related in: MedlinePlus

Mean off-zero lags (±s.e.m.) of /CCmax/ for same- and opposite hemisphere recordings (see text for details).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4128092&req=5

Figure 10: Mean off-zero lags (±s.e.m.) of /CCmax/ for same- and opposite hemisphere recordings (see text for details).

Mentions: We analyzed CCmax and corresponding lags for periods 3, 5, 6, and 7 in 4824 trials with correct behavioral outcomes; 2556 were from LFP pairs within the same hemisphere, and 2268 were from opposite hemispheres. We found the following. (a) CCmax occurred at zero lag in 87.2% of LFP pairs recorded in the same hemisphere and only in 36.4% (244/567) of recordings between opposite hemispheres; these two proportions differed highly significantly (P < 0.001). Conversely, only 12.8% CCmax occurred at off-zero lags in same-hemisphere recordings, as compared to 63.6% in opposite-hemisphere recordings. (b) The magnitude of /CCmax/ varied inversely with lag, such that the longer the lag the weaker the correlation. This effect was much stronger for opposite-hemisphere than same-hemisphere recordings: the correlation coefficient between /CCmax/ and absolute lag was −0.469 for the former, and −0.160 for the latter (P < 0.001 for both). (c) Lags were appreciably longer for recordings from opposite hemispheres (mean ± s.e.m., 5.65 ± 0.154) than from the same hemisphere (0.432 ± 0.048) (Figure 8). In addition, lags for negative CCmax were consistently longer than for positive CCmax (Figure 9). An ANOVA showed that both main effects of recording sites (same/opposite hemisphere) and CCmax sign (positive/negative) were highly significant (P < 0.001 for each, F-test) as was their interaction too (P = 0.001, F-test). This significant interaction reflects the steeper increase in lag (from +CCmax to −CCmax) in the same- than the opposite-hemisphere recordings (Figure 9). (d) Given that a large proportion of lags were at zero, we carried out an additional analysis of off-zero lags, after excluding zero lags. The results are shown in Figures 10, 11. It can be seen that the effect of recording site and CCmax sign were in the same direction as when lags at zero were included (Figures 8, 9). In addition, an ANOVA on the off-zero lag data showed that both main effects of recording sites (same/opposite hemisphere) and CCmax sign (positive/negative) were highly significant (P < 0.001 for each, F-test) as was their interaction too (P = 0.008, F-test).


Cognitive modulation of local and callosal neural interactions in decision making.

Merchant H, Crowe DA, Fortes AF, Georgopoulos AP - Front Neurosci (2014)

Mean off-zero lags (±s.e.m.) of /CCmax/ for same- and opposite hemisphere recordings (see text for details).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4128092&req=5

Figure 10: Mean off-zero lags (±s.e.m.) of /CCmax/ for same- and opposite hemisphere recordings (see text for details).
Mentions: We analyzed CCmax and corresponding lags for periods 3, 5, 6, and 7 in 4824 trials with correct behavioral outcomes; 2556 were from LFP pairs within the same hemisphere, and 2268 were from opposite hemispheres. We found the following. (a) CCmax occurred at zero lag in 87.2% of LFP pairs recorded in the same hemisphere and only in 36.4% (244/567) of recordings between opposite hemispheres; these two proportions differed highly significantly (P < 0.001). Conversely, only 12.8% CCmax occurred at off-zero lags in same-hemisphere recordings, as compared to 63.6% in opposite-hemisphere recordings. (b) The magnitude of /CCmax/ varied inversely with lag, such that the longer the lag the weaker the correlation. This effect was much stronger for opposite-hemisphere than same-hemisphere recordings: the correlation coefficient between /CCmax/ and absolute lag was −0.469 for the former, and −0.160 for the latter (P < 0.001 for both). (c) Lags were appreciably longer for recordings from opposite hemispheres (mean ± s.e.m., 5.65 ± 0.154) than from the same hemisphere (0.432 ± 0.048) (Figure 8). In addition, lags for negative CCmax were consistently longer than for positive CCmax (Figure 9). An ANOVA showed that both main effects of recording sites (same/opposite hemisphere) and CCmax sign (positive/negative) were highly significant (P < 0.001 for each, F-test) as was their interaction too (P = 0.001, F-test). This significant interaction reflects the steeper increase in lag (from +CCmax to −CCmax) in the same- than the opposite-hemisphere recordings (Figure 9). (d) Given that a large proportion of lags were at zero, we carried out an additional analysis of off-zero lags, after excluding zero lags. The results are shown in Figures 10, 11. It can be seen that the effect of recording site and CCmax sign were in the same direction as when lags at zero were included (Figures 8, 9). In addition, an ANOVA on the off-zero lag data showed that both main effects of recording sites (same/opposite hemisphere) and CCmax sign (positive/negative) were highly significant (P < 0.001 for each, F-test) as was their interaction too (P = 0.008, F-test).

Bottom Line: They were observed both within area 7a of the posterior parietal cortex and between symmetric 7a areas of the two hemispheres.Time lags for maximum interactions were longer for opposite- vs. same-hemisphere recordings, and lags for negative interactions were longer than for positive interactions in both recording sites.These findings underscore the involvement of dynamic neuronal interactions in cognitive processing within and across hemispheres.

View Article: PubMed Central - PubMed

Affiliation: Department of Behavioral and Cognitive Neurobiology, Instituto de Neurobiología, UNAM Querétaro, México.

ABSTRACT
Traditionally, the neurophysiological mechanisms of cognitive processing have been investigated at the single cell level. Here we show that the dynamic, millisecond-by-millisecond, interactions between neuronal events measured by local field potentials are modulated in an orderly fashion by key task variables of a space categorization task performed by monkeys. These interactions were stronger during periods of higher cognitive load and varied in sign (positive, negative). They were observed both within area 7a of the posterior parietal cortex and between symmetric 7a areas of the two hemispheres. Time lags for maximum interactions were longer for opposite- vs. same-hemisphere recordings, and lags for negative interactions were longer than for positive interactions in both recording sites. These findings underscore the involvement of dynamic neuronal interactions in cognitive processing within and across hemispheres. They also provide accurate estimates of lags in callosal interactions, very comparable to similar estimates of callosal conduction delays derived from neuroanatomical measurements (Caminiti et al., 2013).

No MeSH data available.


Related in: MedlinePlus