Blinking and Mental Load

The rate of blinking is related to certain mental activities. One common feature of states associated with low blink rates is the presence of concentrated cognitive activity. The purpose of the present study was to determine how blinking is affected by variations in mental load; it was hypothesized that, for a given nonvisual task, blinking would decrease as mental load increased. The first study reported here manipulated memory load by requiring Ss to retain a sequence of 4, 6, or 8 digits. The second study involved mental arithmetic under time pressure; half the trials contained zeros in the sequence of numbers to be summed. In both studies the rate of blinking was low when mental load was high and the rate was high when mental load was low. It is speculated that blinking may disrupt certain cognitive processes and may therefore be inhibited when these processes are active. When mental load is increased, the inhibition of blinking may be an adaptive mechanism which protects vulnerable cognitive processes from interference.