Recent reports suggest, that memory and learning deficits seen to be more specific to schizophrenia (SZ) than previously accepted. Conditional discrimination learning based on eyelid conditioning has been shown to be selectively sensitive in testing temporal lobe function and has the advantage of making minimal demands on attentional capacities and motivation.In our ongoing study, an eyelid conditional discrimination learning task (Daum et al., Behavioral Neuroscience 1991) is used to examine healthy controls and two groups of SZ patients (DSM-III-R paranoid type SZ with predominant positive symptoms and disorganized type with predominant thought disorders). The occurrence of the first conditioned response (FCR) and response frequency to reinforced (CRR) and unreinforced trials (CRU) are quantified.Two paranoid type SZ patients tested up to now, showed high rates of CRRs as well as CRUs (CRR/CRU; 23%/25% and 29%/21%). On the other hand, the two disorganized type patients showed low rates of CRRs and CRUs (CRR/CRU; 2%/4% and 4%/4%). All four patients had the FCR on unreinforced trials and three of them showed delayed FCRs (trials 9, 14, 17) compared to controls.Our preliminary data suggest, that while paranoid as well as disorganized type schizophrenics show reduced discrimination learning capacity, the two subgroups might be differentiated by conditioned response frequency probably due to differences in temporal lobe functions.