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Impaired spatial and non-spatial configural learning in patients with hippocampal pathology.

Kumaran D, Hassabis D, Spiers HJ, Vann SD, Vargha-Khadem F, Maguire EA - Neuropsychologia (2007)

Bottom Line: Our data also provide evidence that residual configural learning can occur in the presence of significant hippocampal dysfunction.Moreover, evidence obtained from a post-experimental debriefing session suggested that patients acquired declarative knowledge of the underlying task contingencies that corresponded to the best-fit strategy identified by our strategy analysis.In summary, our findings support the notion that the hippocampus plays an important role in both spatial and non-spatial configural learning, and provide insights into the role of the medial temporal lobe (MTL) more generally in incremental reinforcement-driven learning.

View Article: PubMed Central - PubMed

Affiliation: Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, 12 Queen Square, London WC1N 3BG, UK. d.kumaran@fil.ion.ucl.ac.uk

ABSTRACT
The hippocampus has been proposed to play a critical role in memory through its unique ability to bind together the disparate elements of an experience. This hypothesis has been widely examined in rodents using a class of tasks known as "configural" or "non-linear", where outcomes are determined by specific combinations of elements, rather than any single element alone. On the basis of equivocal evidence that hippocampal lesions impair performance on non-spatial configural tasks, it has been proposed that the hippocampus may only be critical for spatial configural learning. Surprisingly few studies in humans have examined the role of the hippocampus in solving configural problems. In particular, no previous study has directly assessed the human hippocampal contribution to non-spatial and spatial configural learning, the focus of the current study. Our results show that patients with primary damage to the hippocampus bilaterally were similarly impaired at configural learning within both spatial and non-spatial domains. Our data also provide evidence that residual configural learning can occur in the presence of significant hippocampal dysfunction. Moreover, evidence obtained from a post-experimental debriefing session suggested that patients acquired declarative knowledge of the underlying task contingencies that corresponded to the best-fit strategy identified by our strategy analysis. In summary, our findings support the notion that the hippocampus plays an important role in both spatial and non-spatial configural learning, and provide insights into the role of the medial temporal lobe (MTL) more generally in incremental reinforcement-driven learning.

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Performance of amnesic patients and control subjects, collapsed across condition (spatial or non-spatial). Each block consisted of 50 trials, with presentation of each of the eight patterns occurring pseudorandomly (see Section 2). Error bars reflect standard error of the mean (S.E.M.).
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fig3: Performance of amnesic patients and control subjects, collapsed across condition (spatial or non-spatial). Each block consisted of 50 trials, with presentation of each of the eight patterns occurring pseudorandomly (see Section 2). Error bars reflect standard error of the mean (S.E.M.).

Mentions: A repeated measures ANOVA (factors: condition (spatial, non-spatial), block (1–7), group (control, patient)) confirmed a significant between-subjects effect of group (F(1,8) = 16.3, p = 0.004), with performance of control subjects superior (Fig. 3). There was also a significant effect of block, showing that performance improved over the course of the experiment (F(6,48) = 10.8, p < 0.001). There was no significant effect of condition (F(1,8) = 1.9, p = 0.21), no condition–group interaction (F(1,8) = 3.2, p = 0.11), block–group interaction (F(6,48) = 1.4, p = 0.26), condition–block interaction (F(6,48) = 1.1 p = 0.35) or condition–block–group interaction (F(6,48) = 0.47, p = 0.66).


Impaired spatial and non-spatial configural learning in patients with hippocampal pathology.

Kumaran D, Hassabis D, Spiers HJ, Vann SD, Vargha-Khadem F, Maguire EA - Neuropsychologia (2007)

Performance of amnesic patients and control subjects, collapsed across condition (spatial or non-spatial). Each block consisted of 50 trials, with presentation of each of the eight patterns occurring pseudorandomly (see Section 2). Error bars reflect standard error of the mean (S.E.M.).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2572909&req=5

fig3: Performance of amnesic patients and control subjects, collapsed across condition (spatial or non-spatial). Each block consisted of 50 trials, with presentation of each of the eight patterns occurring pseudorandomly (see Section 2). Error bars reflect standard error of the mean (S.E.M.).
Mentions: A repeated measures ANOVA (factors: condition (spatial, non-spatial), block (1–7), group (control, patient)) confirmed a significant between-subjects effect of group (F(1,8) = 16.3, p = 0.004), with performance of control subjects superior (Fig. 3). There was also a significant effect of block, showing that performance improved over the course of the experiment (F(6,48) = 10.8, p < 0.001). There was no significant effect of condition (F(1,8) = 1.9, p = 0.21), no condition–group interaction (F(1,8) = 3.2, p = 0.11), block–group interaction (F(6,48) = 1.4, p = 0.26), condition–block interaction (F(6,48) = 1.1 p = 0.35) or condition–block–group interaction (F(6,48) = 0.47, p = 0.66).

Bottom Line: Our data also provide evidence that residual configural learning can occur in the presence of significant hippocampal dysfunction.Moreover, evidence obtained from a post-experimental debriefing session suggested that patients acquired declarative knowledge of the underlying task contingencies that corresponded to the best-fit strategy identified by our strategy analysis.In summary, our findings support the notion that the hippocampus plays an important role in both spatial and non-spatial configural learning, and provide insights into the role of the medial temporal lobe (MTL) more generally in incremental reinforcement-driven learning.

View Article: PubMed Central - PubMed

Affiliation: Wellcome Trust Centre for Neuroimaging, Institute of Neurology, University College London, 12 Queen Square, London WC1N 3BG, UK. d.kumaran@fil.ion.ucl.ac.uk

ABSTRACT
The hippocampus has been proposed to play a critical role in memory through its unique ability to bind together the disparate elements of an experience. This hypothesis has been widely examined in rodents using a class of tasks known as "configural" or "non-linear", where outcomes are determined by specific combinations of elements, rather than any single element alone. On the basis of equivocal evidence that hippocampal lesions impair performance on non-spatial configural tasks, it has been proposed that the hippocampus may only be critical for spatial configural learning. Surprisingly few studies in humans have examined the role of the hippocampus in solving configural problems. In particular, no previous study has directly assessed the human hippocampal contribution to non-spatial and spatial configural learning, the focus of the current study. Our results show that patients with primary damage to the hippocampus bilaterally were similarly impaired at configural learning within both spatial and non-spatial domains. Our data also provide evidence that residual configural learning can occur in the presence of significant hippocampal dysfunction. Moreover, evidence obtained from a post-experimental debriefing session suggested that patients acquired declarative knowledge of the underlying task contingencies that corresponded to the best-fit strategy identified by our strategy analysis. In summary, our findings support the notion that the hippocampus plays an important role in both spatial and non-spatial configural learning, and provide insights into the role of the medial temporal lobe (MTL) more generally in incremental reinforcement-driven learning.

Show MeSH
Related in: MedlinePlus