Alice Gomez

Overall, my research activity was focused on the relationship between spatial representations and episodic memory encoding. In particular, the hypothesis of the fundamental role of the egocentric-updating spatial representations for long term memory encoding, has been tested.

As we know, episodic memory encoding of events is associated with two essential processes (a) specific spatio-temporal contextual information during learning and (b) the feeling (consciousness) to travel mentally in his past when an encoded event is remembered (Tulving, 2002). It has been suggested that spatial processing has an essential role in episodic memory, as several central regions such as hippocampus is clearly involved in both, spatial and memory processes (O'Keefe & Nadel, 1978). However, the spatial representations are not uniquely specified and there are several types of spatial representations. My work focused on allocentric and egocentric spatial representations. The allocentric representations ("between objects"), independent of the observer's body position, were classically proposed by the Multiple Trace Theory (Nadel and Moscovitch, 1998). The egocentric representations ("between observer and objects"), body-centered and needing online updating of the spatial environment, referred as egocentric-updating (Farrell, 1998). My main work was to determine which of them - allocentric or egocentric with updating - are the most useful or explain the best episodic long term memory encoding.

During a first behavioral experiment we have shown that maximizing the contextual egocentric-updating processing during the encoding phase of verbal material, induced a better recall of the words than maximizing the allocentric processing (Gomez, Rousset, Baciu 2009, Acta Psychologica).

Subsequently, by using fMRI, we have shown that among the regions activated for the recognized words which were learnt previously in a spatial environment, the medial and lateral parietal cortices were additionally activated only if the spatial environment maximized the egocentric-updating encoding (Gomez, et al. submitted, Cortex). It has been suggested that the activation of parietal regions reflect self- and body consciousness (Bünning & Blanke, 2005; Cavanna & Trimble, 2006). Moreover, the lesions of these regions disturb the episodic memory retrieval (Berryhill, 2007; 2010).

During next experiments, we have reinforced and completed the previous findings with two neuropsychological studies. One of them explored a patient with pure amnesia after bilateral hippocampal lesion, but who also showed deficit of online spatial processing. Specifically, the patient was unable or severely impaired to reproduce a trajectory by drawing, only when the trajectory was learnt during self-motion (egocentric-updating representations) but not during observing the experimenter producing the trajectory (allocentric representations) (Gomez, et al. submitted, Hippocampus). This result was confirmed by a second study of a patient with amnesia after early bilateral lesion of the hippocampus (Gomez, et al. in preparation). The results revealed by the neuropsychological studies suggest that episodic memory deficits might arise from deficit to integrate one's body in the environment (egocentric-updating) rather than deficit to integrate contextual cues of an episode (allocentric).

Finally, in order to reinforce our results revealing the functional role of the egocentric-updating representations in memory encoding, we compared two spatial tasks, each of them using a specific type of spatial representations: one of them used the egocentric-updating and the other one, the egocentric with head-rotation representations. By using fMRI, we have shown that these two types of egocentric spatial representations activated cerebral networks. Only the cerebral network of egocentric-updating included the right hippocampus. In agreement with animal models (Redish, 1997), our results (Gomez, et al. submitted, Brain & Cognition) suggest that the hippocampus is crucial for spatial processing of self-motion (egocentric-updating representations). This constitutes a supplementary argument that memory and spatial processing, are closely related.

INTERNATIONAL JOURNALS PEER-REVIEWED

PUBLISHED

Gomez, A., Rousset, S., & Baciu, M. (2009) Egocentric-updating during navigation facilitates episodic memory retrieval. Acta Psychologica, 32(3):221-7. (pdf)

SUBMITTED

Gomez, A., Rousset, S., Cousin, E., Pichat, C., Guinet, E, Le Bas, J.F., & Baciu, M. Remembering words learned during an egocentric-updating spatial task activates regions involved in self consciousness. An fMRI study. Cortex.

Gomez, A., Rousset, S., Charnallet, A. Spatial Deficits in an Amnesic Case with Hippocampal Damage: Questioning the Multiple Trace Theory. Hippocampus.

Gomez, A., Rousset, S., Cousin, E., Pichat, C., Guinet, E, Le Bas, J.F., & Baciu, M. Allocentric, Egocentric-Updating and Head-Rotation Processing during Spatial Encoding. An fMRI study. Brain & Cognition.

ARTICLES IN PREPARATION

Gomez, A., Cerles, M., Rousset, S. Egocentric perception interferes with allocentric memory. Acta psychologica.

Gomez, A., Bonniot, C, Charnallet, A., Rousset, S. Spatial Deficits in a developmental case of Amnesia with bilateral Hippocampal Damage.

Gomez, A., Bonniot, C, Charnallet, A., Rousset, S. Dissociating "what", where", and "when" components of Episodic memory in a developmental case of amnesia using a new ecological procedure.

PROCEEDINGS

Gomez, A., Rousset, S., Cousin, E., Pichat, C., Guinet, E, Le Bas, J.F., & Baciu. Remembering a word, learned during a spatial contextual task, activates regions involved in self consciousness, when the spatial context relies on automatic "egocentric updating". Cognitive processing, Special issue for the 4th International Conference on Spatial Cognition, 2009. (pdf)

Gomez, A., Rousset, S. (2010). Orienting oneself in space to memorize. Proceedings of pluridisciplinary conference on reference frame and space. (Grenoble) France, April 28-30th 2009. (pdf)

Gomez, A., Rousset, S., Baciu, M. (2008). Navigation processing influences episodic memory. Proceedings of the International Conference on Spatial Cognition 2008, Freiburg, Germany, September 2008, pp. 93-97. (pdf)

ORAL

Gomez, A., Rousset, S., Baciu, M. The role of egocentric-updating in episodic memory. Neurospin (Saclay), France, February 14th 2011.

Gomez, A. Orienting oneself in space to memorize. Pluridisciplinary conference on reference frame and space. (Grenoble) France, April 28-30th 2009.

Perrin, D., Rousset, S, Gomez, A. Subjectivity and spatialisation of episodic remembering. Pole cognition, (Grenoble) France, Juin 2010.

Gomez, A., Rousset, S. Influence of self-centred spatial information on episodic memory. International Congress of Psychology. Berlin (Germany), July 20-25th 2008.

WRITTEN

Gomez, A., Rousset, S., Cousin, E., Pichat, C., Guinet, E, Le Bas, J.F., & Baciu. Is self-referential processing linking egocentric-updating representations and episodic memory through the DNM? The Default Mode Network and other intrinsic networks in health and disease, (Barcelona) Spain, June 4-5th 2010.

Gomez, A., Rousset, S., Cousin, E., Pichat, C., Guinet, E, Le Bas, J.F., & Baciu. Remembering a word, learned during a spatial contextual task, activates regions involved in self consciousness, when the spatial context relies on automatic "egocentric updating". 16th Annual Meeting of the Organization of Human Brain Mapping, (Barcelona) Spain, June 6-10th 2010.

Gomez, A., Rousset, S., Cousin, E., Pichat, C., Guinet, E, Le Bas, J.F., & Baciu. Remembering a word, learned during a spatial contextual task, activates regions involved in self consciousness, when the spatial context relies on automatic "egocentric updating". 4th International Conference on Spatial Cognition, (Rome) Italy, September 14-19th 2009.

Gomez, A., Rousset, S., Cousin, E., Pichat, C., Guinet, E, Le Bas, J.F., & Baciu, M. Distinct and common cerebral correlates related to three (observer-based, survey and navigational route) learning perspectives of a spatial environment: An fMRI study. 15th Annual Meeting of the Organization of Human Brain Mapping, (San Francisco, CA) USA, June 18-23rd 2009.

Gomez, A., Rousset, S., Cousin, E., Pichat, C., Guinet, E, Le Bas, J.F., & Baciu, M. Remembering a word, learned during a spatial contextual task, activates regions involved in self consciousness, when the spatial context relies on automatic "egocentric updating". 9th Conference of the French Neuroscience society, (Bordeaux) France, May 26-29th 2009.

Gomez, A., Rousset, S., Cousin, E., Pichat, C., Guinet, E, Le Bas, J.F., & Baciu, M. Self-consciousness episodic memory and spatial processing. Doctoral school day, (Grenoble) France, May 7th 2009. Best poster price.

Gomez, A., Rousset, S., Baciu, M. Navigation processing influences episodic memory, International Conference on Spatial Cognition 2008, Freiburg, Germany, September 2008.