43, p = .12, partial η2 = .04; no-stereotype exposure condition: Mgirls = 36.92, SDgirls = 5.55; Mboys = 37.12, SDboys = 5.43; stereotype exposure condition: Mgirls = 34.46, SDgirls = 4.68; Mboys = 38.60, SDboys = 4.36; see Fig. 2). In a first

step, we analyzed the effect of stereotype exposure and sex on task-related power (TRP) changes in the upper alpha band. This was done by means of a four-way ANOVA, where STEREOTYPE EXPOSURE and SEX were treated as between-subjects factors, and HEMISPHERE and AREA were ERK inhibitor purchase considered as within-subjects factors. A main effect STEREOTYPE EXPOSURE (F(1,54) = 3.93, p = .05, partial η2 = .07) indicated that participants working in the stereotype exposure condition show higher cortical activation (M = 0.07, SD = 0.03) than participants working in the no-stereotype exposure condition (M = −0.03,

SD = 0.03). No further TRP effects reached statistical significance. We then analyzed the effect of stereotype exposure and sex on neural efficiency. In line with previous studies (Neubauer et al., 2005), the correlation between figural intelligence and brain activation (TRP) during performance of the mental rotation task was used as an inverse indicator of neural efficiency (i.e., a negative correlation would support the neural efficiency hypothesis). Correlations were computed separately for each experimental condition (factors STEREOTYPE EXPOSURE and SEX; i.e., girls and boys working under stereotype exposure or no-stereotype HKI 272 exposure condition, respectively)

and each topographic area of both hemispheres (factors AREA and HEMISPHERE). The tuclazepam TRP was normally distributed in each topographic area for all groups. As depicted in Fig. 3, the IQ-brain activation relationship differs considerably depending on sex and stereotype exposure condition. In the no-stereotype exposure condition, boys showed the expected negative IQ-brain activation relationships especially at centroparietal (r = −.45, p = .05) and temporal areas (r = −.50, p = .04) of the left hemisphere. Girls working under the no-stereotype exposure condition rather tended to show a positive IQ-brain activation relationship especially at frontal areas (r = .48, p = .10) in the right hemisphere of the brain. In the stereotype exposure condition, no significant IQ-brain activation correlations were found, neither for boys nor girls. To sum up, in the no-stereotype exposure condition the neural efficiency hypothesis is supported only for boys, but not for girls. In the stereotype exposure condition no support for the neural efficiency hypothesis was obtained, neither for girls nor boys. This study aimed at further examining sex differences regarding the phenomenon of neural efficiency.