The question of whether studies of human learning provide evidence for distinct conscious and unconscious influences remains as controversial today as ever. Much of this controversy arises from the use of the logic of dissociation. The controversy has prompted the use of an alternative approach that places conscious and unconscious influences on memory retrieval in opposition. Here we ask whether evidence acquired via the logic of opposition requires a dual-process account or whether it can be accommodated within a single similarity-based (...) account. We report simulations using a simple neural network model of two artificial grammar learning experiments reported by Higham, Vokey, and Pritchard that dissociated conscious and unconscious influences on classification. The simulations demonstrate that opposition logic is insufficient to distinguish between single- and multiple-system models. (shrink)

Light and Kennison proposed that bias effects in the forced-choice perceptual identification of words result from a strategy engaged in by subjects to retrieve explicit information about the words. This article enumerates several problems with this proposal and presents new experimental data against it. It is concluded that subjects do not ordinarily employ an explicit retrieval strategy. The data are discussed in the context of the general problem of separating implicit from explicit influences on performance.

Following neural network simulations of the two experiments of Higham, Vokey, and Pritchard , Tunney and Shanks argued that the opposition logic advocated by Higham et al. was incapable of distinguishing between single and multiple influences on performance of artificial grammar learning and more generally. We show that their simulations do not support their conclusions. We also provide different neural network simulations that do simulate the essential results of Higham et al.

Mood has varied effects on cognitive performance including the accuracy of face recognition . Three experiments are presented here that explored face recognition abilities in mood-induced participants. Experiment 1 demonstrated that happy-induced participants are less accurate and have a more conservative response bias than sad-induced participants in a face recognition task. Using a remember/know/guess procedure, Experiment 2 showed that sad-induced participants had more conscious recollections of faces than happy-induced participants. Additionally, sad-induced participants could recognise all faces accurately, whereas, happy- and (...) neutral-induced participants recognised happy faces more accurately than sad faces. In Experiment 3, these effects were not observed when participants intentionally learnt the faces, rather than incidentally learnt the faces. It is suggested that happy-induced participants do not process faces as elaborately as sad-induced participants. (shrink)

By utilizing new information from both clinical and experimental (lesion, electrophysiological, and gene-activation) studies with animals, the anatomy underlying anterograde amnesia has been reformulated. The distinction between temporal lobe and diencephalic amnesia is of limited value in that a common feature of anterograde amnesia is damage to part of an comprising the hippocampus, the fornix, the mamillary bodies, and the anterior thalamic nuclei. This view, which can be traced back to Delay and Brion (1969), differs from other recent models in (...) placing critical importance on the efferents from the hippocampus via the fornix to the diencephalon. These are necessary for the encoding and, hence, the effective subsequent recall of episodic memory. An additional feature of this hippocampalanterior thalamic and the perirhinal–medial dorsal thalamic systems are compromised, leading to severe deficits in both recall and recognition. (shrink)