The authors examined adult age differences in the proficiency of visually scanning across perceived and imagined displays. Participants were asked to indicate whether an arrow in the central region of a square grid ring pointed to a target square. The distance between arrow and target was varied, and all participants showed the expected increase in response times and error rates as scanning distance increased. The arrow and grid display either remained visible until the participant responded (perceptual condition) or disappeared after 50 ms (imagery condition). In both conditions, older participants required more time to scan and made more errors as distance increased than did younger participants. These findings conflict with previous studies showing that perceptual and imagery scanning are preserved with aging. Although methodological factors may have contributed to these differences, further research is needed to elucidate effects of aging on visual scanning.

Adolescent↗

PubMedDate not supplied

Circadian rhythms of Blattella germanica L. as determined by microcalorimetry.

Circadian rhythms of the male cockroach Blattella germanica L. have been observed in thermograms recorded from a microcalorimeter. These endogenous rhythms developed in unentrained individuals after 2 or more 24-h periods without light at 20 degrees C in the microcalorimeter. The rhythm can also be entrained with standard conditions LD 12:12 for a 3-day period.

Animals↗