The Cambridge Face Memory Test (CFMT) and Cambridge Face Perception Test (CFPT) have provided the first theoretically strong clinical tests for prosopagnosia based on novel rather than famous faces. Here, we assess the extent to which norms for these tasks must take into account ageing, sex, and testing country. Data were from Australians aged 18 to 88 years (N = 240 for CFMT; 128 for CFPT) and young adult Israelis (N = 49 for CFMT). Participants were unselected for face recognition ability; most were university educated. The diagnosis cut-off for prosopagnosia (2 SDs poorer than mean) was affected by age, participant-stimulus ethnic match (within Caucasians), and sex for middle-aged and older adults on the CFPT. We also report internal reliability, correlation between face memory and face perception, correlations with intelligence-related measures, correlation with self-report, distribution shape for the CFMT, and prevalence of developmental prosopagnosia.

Combining transcranial magnetic stimulation (TMS) and electroencephalography (EEG) constitutes a powerful tool to directly assess human cortical excitability and connectivity. TMS of the primary motor cortex elicits a sequence of TMS-evoked EEG potentials (TEPs). It is thought that inhibitory neurotransmission through GABA-A receptors (GABAAR) modulates early TEPs (Ͻ50 ms after TMS), whereas GABA-B receptors (GABABR) play a role for later TEPs (at ϳ100 ms after TMS). However, the physiological underpinnings of TEPs have not been clearly elucidated yet. Here, we studied the role of GABAA/B-ergic neurotransmission for TEPs in healthy subjects using a pharmaco-TMS-EEG approach. In Experiment 1, we tested the effects of a single oral dose of alprazolam (a classical benzodiazepine acting as allosteric-positive modulator at ␣1, ␣2, ␣3, and ␣5 subunit-containing GABAARs) and zolpidem (a positive modulator mainly at the ␣1 GABAAR) in a double-blind, placebo-controlled, crossover study. In Experiment 2, we tested the influence of baclofen (a GABABR agonist) and diazepam (a classical benzodiazepine) versus placebo on TEPs. Alprazolam and diazepam increased the amplitude of the negative potential at 45 ms after stimulation (N45) and decreased the negative component at 100 ms (N100), whereas zolpidem increased the N45 only. In contrast, baclofen specifically increased the N100 amplitude. These results provide strong evidence that the N45 represents activity of ␣1-subunit-containing GABAARs, whereas the N100 represents activity of GABABRs. Findings open a novel window of opportunity to study alteration of GABAA-/GABAB-related inhibition in disorders, such as epilepsy or schizophrenia.

Research highlights► Congenital prosopagnosics show weak holistic coding of expression and identity. ► Normal expression recognition can result from compensatory strategies. ► There may be a common stage of holistic coding for expression and identity. ► Holistic coding of identity is functionally involved in face identification ability.