Jennifer E. Sutton

Memory without awareness: pigeons do not show metamemory in delayed matching to sample.

Metamemory, the ability to report on memory strength, is clearly established in rhesus macaques (Macaca mulatta) by converging evidence from several paradigms. In contrast, A. Inman and S. J. Shettleworth (1999) found no conclusive evidence of metamemory in pigeons. The authors studied pigeons further in 3 paradigms, with multiple tests of metamemory in each. Pigeons encountered a safe alternative to a matching-to-sample test either before (Experiment 2) or concurrently with (Experiment 3) the matching test. Choices of the safe option did not vary consistently with matching accuracy or change in trials with omitted samples in the way predicted for an animal with metamemory. In Experiment 4, confidence ratings following completion of the matching test also did not vary consistently as predicted by metamemory.

Multiple systems for spatial learning: dead reckoning and beacon homing in rats.

Rats homed with food in a large lighted arena. Without visual cues, they used dead reckoning. When a beacon indicated the home, rats could also use the beacon. Homing did not differ in 2 groups of rats, 1 provided with the beacon and 1 without it; tests without the beacon gave no evidence that beacon learning overshadowed dead reckoning (Experiment 1). When the beacon was at the home for 1 group and in random locations for another, there was again no evidence of cue competition (Experiment 2). Dead reckoning experience did not block acquisition of beacon homing (Experiment 3). Beacon learning and dead reckoning do not compete for predictive value but acquire information in parallel and are used hierarchically.

Landmark use by squirrel monkeys (Saimiri sciureus)

Two squirrel monkeys searched for a reward buried in 1 of 144 holes that formed a 12×12 grid (48×50 cm). An array of vertical, colored landmarks was placed on the grid, and their locations on the grid were changed from trial to trial. During training trials, the mealworm reward was placed either in the center of a square array of landmarks (Experiments 1 and 3) or midway between two landmarks (Experiment 2). On nonrewarded test trials, the monkeys searched among landmarks placed in the same arrays as those used in training and among landmarks placed in an expanded array (Experiments 1 and 2) or in an array intermediate between the two arrays used in training (Experiment 3). Distributions of searches on test trials indicated that the monkeys searched mostly within the configuration of the landmarks but that they had not coded the location of the reward as being either in the middle of the landmarks or at a fixed distance and direction from an individual landmark.

Spinning in the Scanner: Neural Correlates of Virtual Reorientation

Recent studies have used spatial reorientation task paradigms to identify underlying cognitive mechanisms of navigation in children, adults, and a range of animal species. Despite broad interest in this task across disciplines, little is known about the brain bases of reorientation. We used functional magnetic resonance imaging to examine neural activity in adults during a virtual reality version of the reorientation task. Three environments that varied in the cues provided were studied: a rectangular room with 4 identical gray walls (Geometry), a square room with 3 gray walls and 1 red wall (Feature), and a rectangular room with 3 gray walls and 1 red wall (Feature + Geometry). Multiple areas within the medial temporal lobe (MTL) showed increased activation when a feature was present compared with when reorientation was based only on geometric cues. In contrast, reliance on geometric cues significantly activated a number of non-MTL structures, including the prefrontal cortex and inferior temporal gyrus. These results provide neural evidence for processing differences between the 2 types of cue as well as insight into developmental and comparative aspects of reorientation.

Geometry Three Ways: An fMRI Investigation of Geometric Information Processing during Reorientation.

The geometry formed by the walls of a room is known to be a potent cue in reorientation, yet little is known about the use of geometric information gleaned from other contexts. We used functional magnetic resonance imaging to examine neural activity in adults while reorienting in 3 different environments: the typical rectangular walled room, a rectangular configuration of pillars in an open field, and a rectangular floor in an open field. Behavioral response patterns for the 3 environments were similar, but pairwise contrasts of brain activation revealed differences at the neural level. We observed greater medial temporal lobe (MTL) involvement when reorienting with the pillars versus the walls and floor. In addition, the walled room selectively engaged areas of posterior parahippocampal cortex corresponding to the parahippocampal place area, when compared with the floor. Finally, a conjunction analysis of the 3 geometry conditions, compared with a control task, revealed activation in the primary auditory cortex that was common to all geometry conditions. These findings add to growing evidence that adults use verbal processes to encode environment geometry and that the reorientation tasks that young children find difficult are particularly hippocampus-dependent.

Internal Sense of Direction and Landmark Use in Pigeons (Columba livia)

The relative importance of an internal sense of direction based on inertial cues and landmark piloting for small-scale navigation by White King pigeons (Columba livia) was investigated in an arena search task. Two groups of pigeons differed in whether they had access to visual cues outside the arena. In Experiment 1, pigeons were given experience with 2 different entrances and all pigeons transferred accurate searching to novel entrances. Explicit disorientation before entering did not affect accuracy. In Experiments 2-4, landmarks and inertial cues were put in conflict or tested 1 at a time. Pigeons tended to follow the landmarks in a conflict situation but could use an internal sense of direction to search when landmarks were unavailable.

The hippocampus is not a geometric module: processing environment geometry during reorientation

The hippocampus has long been known to play a role in allocentric spatial coding, but its specific involvement in reorientation, or the recalibration of a disrupted egocentric spatial representation using allocentric spatial information, has received less attention. Initially, the cognitive literature on reorientation focused on a “geometric module” sensitive to the shape formed by extended surfaces in the environment, and the neuroscience literature followed with proposals that particular MTL regions might be the seat of such a module. However, with behavioral evidence mounting that a modular cognitive architecture is unlikely, recent work has begun to directly address the issue of the neural underpinnings of reorientation. In this review, we describe the reorientation paradigm, initial proposals for the role of the MTL when people reorient, our recent work on the neural bases of reorientation, and finally, how this new information regarding neural mechanism helps to re-interpret and clarify the original behavioral reorientation data.

Hangar talk survey: using stories as a naturalistic method of informing threat and error management training.

Objective: The current study developed an online hangar talk survey (HTS) to solicit narratives describing challenging scenarios that professional pilots encountered during the hours-building phase of their career. Background: The predicted pilot shortage will effectively reduce the minimum flying hours required for pilots to be hired at an airline, resulting in less opportunity to develop nontechnical skills naturalistically. To compensate, threat and error data from the hours-building phase of a pilot’s career are required to inform training development. Pilots often share stories of such experiences, colloquially termed “hangar talk.” Method: The HTS gathered 132 narrative descriptions of general aviation (GA) events from pilots along with the event’s impact and whether the pilots would react differently if the scenario were encountered again. Results: The distribution of threats reported by GA pilots was similar to that reported at the airline level. Logistic regression analysis revealed that decision-making errors were associated with recognition of the need to react differently in the future, and decision-making errors and proficiency errors were associated with greater perceived impact on skill development. Conclusion: The current HTS solicited an array of data similar to the findings of airline-based threat and error observations. Pilots perceive decision-making and proficiency errors as impactful on skill development. Application: An HTS can be used to gather naturalistic threat and error data and to create a database of operational stories that can be used to develop nontechnical training based on narrative thought.