DO I HAVE YOUR ATTENTION BRANCH !1

Innocence Branch

Dr. Joshua Shive

PSYC 5060

April 19, 2015

Do I Have Your Attention: Examining the Influence of Unconscious Memories on Behaviors and

Perceptions

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Abstract

Current empirical data tells us that there is widespread agreement that the hippocampus

is imperative “for explicit episodic memory retrieval” (Hannula & Ranganath, 2009), but

whether this region can also support indirect expressions of relational memory when explicit re-

trieval fails is polemical. The unifying theme of this research report is a focus on the specific

concept that unconscious (i.e., implicit or non-declarative) memories exert powerful influences

on behaviors and depend on distinct neural mechanisms from consciously accessible (i.e., explic-

it or declarative) memories.

The first article included in this review was Looking As If You Know: Systematic Object

Inspection Precedes Object Recognition from Holm, Eriksson, & Andersson, (2008). Their work

focused on how individuals can look at the very object they are searching for, without conscious-

ly seeing it. Holm et al., (2008) sought to answer the query ‘How do we select object relevant

information before we become aware of the object?’ using two recognition experiments involv-

ing pictures of fragmented objects. The experiments were labeled Experiment 1 and Experiment

2. Investigators report that the participants were “looking at the objects as if they knew them be-

fore they became aware of their identity,” Holm et al., (2008).

In Experiment 1, the participants preferred to focus on the target object rather than the

control region prior to explicit recognition. The participants examined the target as if they recog-

nized it sometime around 9 fixations prior to explicit recognition (the control was 25 fixations).

The investigators report giving participants training in identifying fragmented objects on the

practice set before the actual test in order to aerate the number of sighted items in Experiment 1.

Each fractured picture was preceded by a label (appearing for 3 s) during actual testing. Frac-

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tured pictures were displayed for 60 s unless recognition (as indicated with a button press) came

first. Pictures were displayed for an appended 3 s post button press to stratify data after recogni-

tion. Participants were directed to report the color, the position, and the identity of the target item

after every trial.

In Experiment 2, the investigators tested the sway of semantic knowledge in contriving

object inspection preceding lucid recognition. Ergo, they attribute more precise knowledge re-

garding target identity (as indicated by eye movements) caused participants to scan the splintered

catalyst more dexterously (e.g., non-target regions were rejected faster when participants knew

the target object’s name). Holm et al., (2008) directs impending investigations to focus on diffi-

cult recognition tasks in more natural conditions, as this was a limitation of their study.

It's In My Eyes, but It Doesn't Look That Way to Me (Kumaran, & Wagner, 2009) seemed

relevant to this review because of the investigators’ hypothesis that eye movements are a display

of unconscious relational memory even when participants’ overt memory decisions are in error.

The apex of their investigation dealt with the relationship between mnemonic awareness and

hippocampal function. The researchers explored the notion that implicit memories may exert

strong dominion on actions dependent on incisive neural mechanisms from explicit memories. To

accomplish this, Kumaran & Wagner (2009) first classified test trials in accordance ‘to whether

participants disproportionately viewed either the matching face or one of the distractor faces

(e.g., DMP & DNMP trials). Their findings report that the viewing times of the matching face on

DNMP trials were significantly less than of the selected face on DMP trials. The investigators

stated recognitions to be ‘as early as 500–1000 ms after the onset of the face array and consistent

with an influence of relational memory retrieval during DMP trials,’ Kumaran, & Wagner (2009).

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The researchers conclude that survival in a constantly evolving environment depends on the abil-

ity to quickly express memory (e.g., recognizing the venomous snake as it crosses your path on a

nature trek, or a child remembering not to touch a hot stove/fire because fire burns after getting

too close to the stove and receiving a painful heat sensation the last time their mother was baking

along with the mother telling the child that the red glow of the fire is “hot”).

In the 2009 article, The Eyes Have It: Hippocampal Activity Predicts Expression of Mem-

ory in Eye Movements, Hannula,& Ranganath used functional magnetic resonance imaging

(fMRI) with concurrent indirect, eye-movement-based memory measures, to obtain evidence that

hippocampal activity predicts expressions of relational memory where explicit retrieval failed. In

addition, activity in the lateral prefrontal cortex and functional connectivity between the hip-

pocampus and prefrontal cortex were greater for correct trials than for incorrect trials.

The next article of this review was The Influence of Explicit and Implicit Memory Pro-

cesses on Experience-Dependent Eye Movements. The stated objective was to clarify whether

implicit or explicit memory processes influence “experience-dependent eye movements” (Re-

ichelt, Kühnel, & Dal Mas, 2013) utilizing novel, repeated or manipulated photographed scenes

(with objects added or removed). Participants were consequently shown specific scenes dis-

tributed over a three day span for the second half of the experiment and asked to determine if the

scenes were novel, repeated or manipulated. Reichelt et al., (2013) report espied “experience-de-

pendent eye movements” when the participants were mindful of changes such as collusions and

iterations, as well as when participants were unaware. The investigators concluded that both ex-

plicit and implicit memory processes have an influence on experience-dependent eye move-

ments.

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The final article of this review, Attending to Remember and Remembering to Attend

Dudukovic, & Wagner, (2006) was included because of the focus on the bidirectional interactions

between attention and memory due to their symbiotic relationship. This report also echoed some

of the previous studies, highlighting the importance of the hippocampus for explicit memory.

This research was predicated upon the earlier works of Turk-Browne and colleagues (2006) and

Summerfield (2006). The aforementioned studies examined ‘the common impact of attention on

implicit and explicit memory’ and memory-guided attentional orienting, respectively. Dudu-

vkovic & Wagner (2006) propose that these works both reflect the prognostic power of explicit

memory, implicit memory or both.

The corollary of memory in acquiescing to attentional biases to be ‘apparent with as little

as 100 ms between scene and target onset,’ Turk-Browne et al. (2006) and Summerfield (2006)

reports are the second highlights. According to Dudukovic, & Wagner (2006), this increases the

chances for reflection of a rapid expression of implicit knowledge. The investigators also stated

that comprehending the cognitive and neural mechanisms (underlying both of these abilities) is

dependent on specifying how and when these systems interact. One tenant of this report is how

memory for the past may serve to direct how attention can be dedicated presently. As perception

can be expedited via explicit memory, a likely prognosis is that we suffer when our conjectures

are distorted.

Findings from many recent empirical experiments suggest that relational memory may be

evident in patterns of eye movements even when conscious recollection fails. Preston and

Gabrieli, (2008) argued that contextual cueing may depend on composed representations sup-

ported by “hippocampal regions such as the perirhinal cortex rather than the kind of relational

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memory representations thought to depend on the hippocampus.” This is in accordance to a re-

cent report by Hannula & Ranganath, (2009) entitled The Eyes Have It: Hippocampal Activity

Predicts Expression of Memory in Eye Movements. Sensory memory sustains all incoming in-

formation for seconds or fractions of a second and visual information is encoded via sensory

memory. That information is transposed into short-term memory by rehearsal and ultimately

moves to the long-term memory through memorization. Therefore, if any step in the process be-

comes distorted (such as the case with distraction, misinformation, false cues during the re-

hearsal phase, or intrusion errors), the memories can be flawed.

Eichenbaum and Cohen (2001) reported that this is known as relational memory bind-

ing. According to this paradigm, relational representations may be expressed without concomi-

tant conscious awareness. In 1978, Loftus and colleagues studied the misinformation effect in

which they had participants look at a series of pictures that followed a car as it stops, turns, and

then crashes. The misinformation effect refers to the impairment in memory for the past that

arises after exposure to misleading information. One group was asked if the car stopped at the

stop sign, while the other group was asked if the car stopped at the yield sign.

An interesting fact about this study is that each participant’s answer depended on which

question they heard immediately following the accident. Therefore when asked to recall informa-

tion, there is a possibility that the misleading post-event information changes memory entirely. In

the real world, misinformation comes in many forms for individuals such as witnessing a trau-

matic event, students being led with misleading questions on an exam, suggestive techniques

from defense attorneys during a court trial, or reading conflicting media coverage about an event.

Misinformation can enter consciousness and can cause contamination of memory.

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Summary

In summary, each of the studies in this review were relevant for exploring how attention

can determine what facets of our daily experiences are cached in implicit and explicit memory

and how they can shape subsequent perception via attention control once encoded. Kumaran &

Wagner (2009) examined current empirical research to determine if a relationship between mne-

monic awareness and hippocampal function exists. Hannula & Ranganath, (2009) evince that eye

movements may avow memory for traces of former experiences. Dudukovic, & Wagner, (2006)

reveal bidirectional interactions between attention and memory. Holm et al., (2008) surmise that

auguring information sampling generally antedates lucid object recognition and relegating object

recognition to a function of implicit inference as proposed by Helmholtz (1910). During the final

discussion section of the Influence of Explicit and Implicit Memory Processes on Experience-de-

pendent eye Movements, Reichelt et al., (2013) report their results suggest an influence on expe-

rience-dependent eye movements from explicit as well as implicit memory processes. The report

concludes with the suggestion that future studies might expand their inquiry with the addition of

the impact of scene complexity more thoroughly.

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References

Dudukovic, N. M., & Wagner, A. D. (2006). Attending to remember and remembering to attend.

Neuron, 49(6), 784-787.

Eichenbaum, H. (2004). Hippocampus: cognitive processes and neural representations that un-

derlie declarative memory. Neuron, 44(1), 109-120.

Hannula, D. E., & Ranganath, C. (2009). The eyes have it: hippocampal activity predicts expres-

sion of memory in eye movements. Neuron, 63(5), 592-599.

Holm, L., Eriksson, J., & Andersson, L. (2008). Looking as if you know: Systematic object in-

spection precedes object recognition. Journal of Vision, 8(4), 14.

Kumaran, D., & Wagner, A. D. (2009). It's in my eyes, but it doesn't look that way to me. Neu-

ron, 63(5), 561-563.

Reichelt, B., Kühnel, S., & Dal Mas, D. E. (2013). The Influence of Explicit and Implicit Memo-

ry Processes on Experience-dependent eye Movements. Procedia-Social and Behavioral

Sciences, 82, 455-460.

Tousignant, J.P., Hall, D., and Loftus, E.F. 1986. Discrepancy detection and vulnerability to mis-

leading post-event information. Mem. Cogn. 14:329 -338.