Summary

1. Latencies decrease with age in the nonlagged population. This trend is not evident in the entire population because immature nonlagged cells overlap in latency with lagged cells.
2. Lagged cells develop stronger inhibition late in postnatal development, giving them their characteristic absolute phase lag.
3. ON/OFF cells may exist in the A-layers of kittens. It is often difficult to tell whether cells are lagged ON (OFF) or nonlagged OFF (ON) as well.
4. Despite the difficulties in classifying cells, some neurons are clearly lagged or nonlagged even in 5 week old kittens. Relatively mature cells exist early in development, but are much less common.
5. Predictions from these data are that cortical direction selectivity:
• is less prominent at low temporal frequencies in young kittens, because the variance in absolute phase is so low; and
• is ubiquitous at higher temporal frequencies, because of the huge variance in latencies in these kittens.

Date created: November 5, 1997
Last modified: November 5, 1997
Copyright © 1997, Alan Saul
Maintained by: Alan Saul
Alan Saul