Mental-rotation task response times from 12 studies involving 505 adults--251 males and 254 females--were used to evaluate 5 hypotheses concerning sex differences derived from an X-linked genetic model. The model assumes that task facilitation in speed of mental rotation is mediated by a recessive gene. Four hypotheses derived from the model were…

Children and adults were tested on six speeded perceptual-motor and cognitive tasks, including a (1) response time task; (2) button tapping task; (3) pegboard task; (4) coding task; (5) picture matching task; and (6) mental addition task. Age-related change in processing time on most of these tasks was described by a single exponential function.…

Tested adults and children (age 6 to 16 years) on 4 speeded tasks that included 19 experimental conditions. The 6- to 16-year olds' response times decreased with age as a function of adults' response times. (MM)

Analysis of 22 mean response times (RTs) for children with specific language impairment (SLI) found that SLI children's RTs increased linearly as a function of RTs for age-matched non-SLI control children. Intergroup differences in processing speed between children with and without SLI reflect some general component of cognitive processing.…

A review of 45 published studies yielded 518 pairs of response times (RTs) consisting of a mean RT for persons with mental retardation and the corresponding mean RT for persons without mental retardation. RTs of individuals with mental retardation increased linearly as a function of RTs for persons without mental retardation in corresponding…

Assesses performance of 9-, 13-, and 20-year-olds on 3,840 trials of a mental rotation task in which subjects judged if pairs of stimuli presented in different orientations were identical or mirror images. Results are discussed in terms of possible mechanisms underlying the impact of practice. (Author/NH)

Children and adults were tested on a mental rotation task in which letters were presented in different orientations. The task was performed by itself or with a memory task. Results indicated that the relation of response time to stimulus orientation in the rotation task was the same in both conditions. (BC)

Tests two hypotheses concerning developmental change in the speed of cognitive processes: (1) age differences in processing time reflect changes that are specific to particular tasks, and (2) age differences in processing speed do not reflect task-specific change but are due instead to more general developmental change. (HOD)

Examined whether age-related change in naming time reflects automatic access of familiar names because of greater familiarity with the named objects or global change in speed of processing. The path analyses and structural-equation modeling of 8- to 13-year olds were consistent with the second explanation. Time and age were linked to reading…

Three experiments focused on the function relating children's response time to adults' response time in corresponding conditions. In all experiments, children's response times increased in a linear manner as a function of adults' response times. (BB)