Learning and Memory

DIFFERENCES IN CEREBELLAR FUNCTION IN DYSLEXIA

Aimee Boegle, Rebecca Haberle, Lisa Tyler, Angie Pistunw, & Joan M. Coffin, Ph.D.

King’s College

Dyslexia, the most common learning disability, is often described as a failure to achieve language and grammar skills commensurate with age. Mastery of these skills is typically associated with higher cognitive mechanisms located in the neocortical areas of the cerebrum. Recent research has looked beyond these traditional areas and the use of neuroimaging techniques has revealed subtle signs of cerebellar dysfunction in dyslexics. To test the possible role of the cerebellum in the behavioral differences most notable among dyslexics, we chose the cerebellar dependent learning task, Eyeblink classical conditioning (EBCC).

We have recently demonstrated that identified dyslexics fail, over two days, to achieve learning in this paradigm, performing at a rate of 10%, compared to non-dyslexics who learn at a rate of 60% (Coffin & Jones, 1999). Deficits in EBCC were notable (p<0.001), even though these dyslexic individuals performed as well as their peers on a word-memory task.  A second significant difference between these groups was the slow response time for the dyslexic participants, indicating a functional difference in the cerebellar cortex.

In the present study we tested identified dyslexic individuals over a five-day period to assess changes in response time and evidence of learning the EBCC task. The results of the study demonstrate that dyslexics fail to achieve EBCC, even after five conditioning sessions, and performed at a rate significantly lower than non-dyslexics and learning disabled non-dyslexics (p<0.015; p<0.001). Response latency was also significantly different across groups (p<0.05, dyslexics /non-dyslexics; p<0.005 dyslexics/learning disabled). Although dyslexics failed to achieve learning in this paradigm, we noted a decrease in response latency across the five sessions. By session five, latency approached 400 ms, indicating that the neural substrates underlying EBCC were engaged.

The decrease in response latency is a significant finding, suggesting that exposure to EBCC may strengthen the neural connections involved in EBCC, specifically in the cerebellum. This study also suggests cerebellar participation in the neural network necessary for reading and language skills.
 

CEREBELLAR TASK DEMAND INTERFERES WITH PERFORMANCE IN TWO MEMORY SYSTEMS

 Jennifer Marston, Mary Ann Koza, Amy Day & Joan M. Coffin

King’s College

Traditionally, it has been assumed that explicit and implicit memory systems engage separate neural pathways. Thus, learning verbal tasks (explicit) and eyeblink classical conditioning (EBCC; implicit) should occur independently, whether they are learned separately or concurrently. Recent neuroimaging studies have suggested that the cerebellum may be part of a verbal learning network. We have previously demonstrated differences in EBCC performance among dyslexics, which may reflect functional differences in this structure. In the present study concurrent verbal and EBCC learning was compared in dyslexic and non-dyslexic college students.

Thirty participants (15 dyslexic, 15 non-dyslexic; 5 per group) were assessed on verbal learning, EBCC alone, or the concurrent presentation of both tasks. The verbal task was 25 words spliced into a silent film, presented singly for 500 ms at a variable ITI of 20-40 s. Recall of words was assessed at the end of the session. For EBCC, delay paradigm, each conditioning trial consisted of a 500 ms tone, which coterminated with a 100 ms corneal airpuff. Sessions consisted of 64 paired, and 8 tone-alone trials. A conditioned response (CR) was scored when a blink response was recorded prior to the airpuff.

There were no significant within group differences for EBCC. Dyslexics scored 5% CRs in the single task and 10% CRs in the dual task format. Non-dyslexic EBCC results were 50% and 63%, respectively. For the verbal task, dyslexics performed at a similar rate, averaging 11.2 and 10.5 words, respectively. Non-dyslexics recalled significantly fewer words in the dual task (8.3) than in the words-alone format (14.8; p<0.03).

The results suggest a common cerebellar learning component in non-dyslexics for these two memory systems, with dual task demand interfering with performance in word recall. Among dyslexics, the data suggest the cerebellum was not engaged in either task. We hypothesize that dyslexics employ a compensatory, non-cerebellar verbal learning mechanism, enabling them to perform equally well on the verbal task, regardless of presentation format. As dyslexics do not learn EBCC, their performance on this task was not affected.
 

CEREBELLAR DEPENDENT TASK DISCRIMINATES AD/HD

Josh O'Neill, Cheryl Marshall, Erin Kirby, Nick Belasco, & Joan M. Coffin Ph.D.

King’s College
Cognitive Neuroscience Laboratory

Attention Deficit/Hyperactive Disorder (AD/HD) is a behavioral disorder typically diagnosed in childhood. High levels of physical activity, impulsive and immature behavior, and short attention span characterize the condition. AD/HD can trigger extensive social, emotional and educational problems. Due to the symptoms associated with AD/HD, such as lack of concentration and hyperactivity, individuals often have difficulty learning new information. Recent evidence suggests that learning activates specific areas of the cerebellar cortex. To identify the possible differences in the way AD/HD individuals learn we chose to use the cerebellar learning dependent task, eyeblink classical conditioning (EBCC).

Identified AD/HD (n=5) and non-AD/HD (n=5) individuals were tested over two sessions, with 48 hours between each session. Because of the symptomology of AD/HD, we tested both acquisition of EBCC and response latency, in the delay paradigm. Each conditioning trial consisted of a 500 ms tone that coterminated with a 100 ms corneal airpuff. The airpuff causes a reflexive blink response. Learning occurred when the participant blinked after the tone, and prior to the administration of the airpuff. For each session, participants were presented with 64 paired trials and 8 trials of tone only. The number of conditioning trials needed to reach the learning criterion of 8/9 CRs was then compared.

The results indicate that AD/HD participants condition at a significantly faster rate on the first day (p<.0168, %CRs). Response latency was also significantly different (p<.0013), with AD/HD participants responding more quickly to the stimuli. The results of the second day of conditioning demonstrate no significant difference in conditioning between the non-AD/HD and AD/HD participants.

This research demonstrates that AD/HD individuals learn EBCC more quickly then do normal individuals, however their responses match non-AD/HD individuals after continued conditioning. One possible explanation may be the degree of sensitivity to new stimuli among this population. A second major finding of this research is the ability of EBCC to discriminate between different types of learning disabilities. Our laboratory has previously demonstrated that EBCC discriminates dyslexia. These latest results indicate that EBCC may be a valuable tool in diagnosing specific learning disabilities.
 

Perception

GENDER DIFFERENCES IN BODY IMAGE PERCEPTION AMONG UNDERGRADUATES

Jilda Hodges, Jena Iannuzzelli, Mindy Solomon, John Venuti, & Catherine Chambliss

Ursinus College

One of the most distressing problems reported involves concern over physical appearance.  Females, in particular, have been found to be highly dissatisfied with the overall appearance of their bodies.  Not surprisingly, distortions in body image have been linked to chronic dieting, eating disorders, and decreased self-esteem.  In a society that emphasizes acultural ideal of female slenderness, it remains no surprise that there are disturbances in body image.  Undoubtedly, there remain differences in the ideal figure strived for by members of each sex.  Furthermore, perceptions of the self most often show more distortion among women.  Certainly, an individual's satisfaction and perceptions can influence their lifestyle. The present study examines body image satisfaction and perceptions among college students.  The body scale used by Stunkard et al. (1980) was used to
determine the current shape of self and the ideal body shape across gender.  This study found that women's opinion of the ideal female body shape was significantly thinner than the males' opinion of the ideal female.  Women were found to be more distressed over their current weight and to feel a stronger need to lose weight, while men were more likely to desire to gain
weight and to have used dietary supplements for this.  One noteworthy finding involves perception of what the opposite sex finds attractive.  Both men and women agree that the opposite sex desires large breasts or pecs; tight, round buttocks; and tight, defined abdominal muscles.
 

GENDER DIFFERENCES IN PERCEPTIONS OF THE HEALTHLINESS OF FOODS

Michael Oakes & Carole Slotterback

University of Scranton

Our perceptions of the healthiness of foods are thought to influence what we decide to eat.  Reportedly, women (as compared to men) eat more nutritious foods and are more likely to consider health issues when deciding what to eat.  However, until now, no one has investigated possible gender differences in perceptions of the healthiness of foods.  In the present study, men and women answered questions pertaining to nutritional habits, then rated a variety of foods according to their healthfulness.  Results indicated that women, compared to men, tended to emphasize fat content over nutrient levels when deciding what foods are healthy.  If perceptions of food health influence consumption, it is likely that females, as compared to males, would be more likely to suffer from malnutrition.
 

GROUP SIZE, EXPECTATIONS ABOUT HUMOR, AND HUMOR RESPONSES

Caryn Crane, David Gordon, David Kozloff, Heather Porter, Christina Rosenber, & Bernard C. Beins

Ithaca College

When people rate jokes for humor value, the responses indicate cognitive evaluation.  Such evaluation reflects only a limited aspect of reactions to humorous material.  In this study, participants rated a set of 20 jokes, expecting that they would be very funny or not very funny.  Some participants engaged in this task after engaging in a group puzzle
solving task; other participants did so individually.  We recorded their ratings and displays of mirth (e.g., laughing and smiling).  The results revealed that after a group bonding activity, participants’ expectations about whether jokes were going to be funny affected their ratings, based on their expectations about the jokes. The presence of others affects participants’ ratings of jokes.  Building on previous research, we also concluded that the mere presence of others also affects ratings of jokes, but not mirth responses.  The dynamics of individual groups may be critical in the expression of mirth.
 

Neuroscience I

CHRONIC MORPHINE AUGMENTS REWARD COMPARISON IN RATS.

R.A. Wheeler, S.M. Ballard, C.S. Freet, & P.S. Grigson

Penn State College of Medicine

Intake of a saccharin solution is decreased when it is followed by either access to a more palatable sucrose solution or administration of either a drug of abuse or an illness-inducing drug. Our preliminary studies have shown that this associative phenomenon is identical in Lewis and Fischer 344 rats when the illness-inducing agent LiCl follows access to saccharin. However, the suppressive effects of sucrose and drugs of abuse are greater in reward-preferring Lewis rats than in both Fischer 344 and Sprague-Dawley rats. Therefore, we hypothesized that known differences in the VTA-NAc pathway of Lewis rats (Nestler, 1995) are mediating these behavioral differences. In order to test this, Sprague-Dawley rats were implanted subcutaneously (sc) with a 75 mg morphine pellet or placebo for 5 days to induce “Lewis-like” brain changes in the VTA-NAc pathway (Nestler, 1995). These rats were then tested in three associative experiments using parameters known to yield small suppressive effects. (1) Water deprived rats were given brief access to 0.15% saccharin followed by either a saline or LiCl (0.002M,ip) injection every other day for 16 days. (2) Food deprived rats were presented with a light cue and then given brief access to 0.15% saccharin followed by either 0.15% saccharin or 32% sucrose for 16 days. (3) Water deprived rats were given brief access to 0.15% saccharin followed by either a saline or cocaine (8mg/kg,sc) injection every other day for 16 days. The results showed that, while chronic morphine exerted no effect on LiCl-induced suppression of saccharin intake, it significantly augmented both sucrose- and cocaine-induced suppression of saccharin intake. The pattern obtained across these experiments mirrors previous findings with Lewis rats, implicating the mesolimbic dopamine system in these reward comparison processes. Supported by DA 05932 and DA 09815.
 

cAMP-DEPENDENT PROTEIN KINASES WITHIN THE NUCLEUS ACCUMBENS CORE MEDIATE APPETITIVE INSTRUMENTAL LEARNING.

 A.E. Baldwin1*, K. Sadeghian2, and A.E. Kelley

Neuroscience Training Program and Dept. of Psychiatry, University of Wisconsin-Madison

We have recently shown that co-infusion of low doses of D1 and NMDA receptor antagonists into the accumbens core inhibits appetitive instrumental learning.  To investigate the possible intracellular mechanisms activated in this learning process, we have examined the effects of intra-accumbens microinfusion of Rp-cAMPS and Sp-cAMPS, which, respectively, inhibit and stimulate cAMP-dependent protein kinases I and II.  Rats chronically implanted with cannulae aimed at the accumbens were food-deprived and tested for acquisition of lever pressing for sucrose pellets over ten days.  On the first four days of testing all animals received microinfusions of drug or vehicle.  In the first experiment, animals received infusions of either Rp-cAMPS (5 or 20 nmol), Sp-cAMPS (5 or 20 nmol), or vehicle immediately before testing.  In a second experiment animals received infusions of either Rp-cAMPS (10 nmol) or vehicle immediately after testing.  In a third experiment animals received Rp-cAMPS (10 nmol) or vehicle one hour after testing.  On days 5-9 animals in all experiments were tested without infusion.  On day 10, animals in the first experiment  received an additional pre-test infusion as on days 1-4.  Pretreatment with either Rp-cAMPS or Sp-cAMPS dose-dependently attenuated acquisition of the learned behavior.  Treatment with Rp-cAMPS immediately after or one hour after testing also inhibited learning.  These results indicate that activation of cAMP-dependent protein kinases within the accumbens may mediate appetitive instrumental learning.  As Sp-cAMPS, the kinase activator, also inhibited learning, this suggests that there is a narrow range of kinase levels that allows for learning of such tasks.  Supported by NIDA grant # DA04788.
 

RELATIONSHIPS BETWEEN REPRODUCTIVE BEHAVIOR AND FERTILITY

Michael J. Mahometa & Michael Domjan

University of Texas at Austin

Preliminary data collected by Domjan and Çetinkaya in the Texas Quail Lab indicated that copulatory anticipation by both partners increases the number of fertile eggs that are produced as a result of a mating episode.  Copulatory anticipation was achieved through pairings of a conditioned stimulus (CS) with copulatory opportunity (US).  The present study was designed to replicate these original findings, and to determine which sexual partner was primarily responsible for the increase in fertility.  In addition, unlike the original experiment, the present study was designed to document behavioral correlates of increased fertility.

The design of the experiment involved providing copulatory tests for pairs of animals in which one partner anticipated the copulatory interaction and the other did not.  All trained animals were given predictable CS-US pairings, making the CS predictive of copulatory opportunity.  Control subjects were given random CS/US presentations.  Trained males were tested with untrained females and vice versa.  All pairs of animals were tested with a CS presentation.  Eggs from each female were collected, incubated, and candled for fertility.  All tests were videotaped for behavioral analysis.  Because of the link between energy expenditure and fertility, a behavioral index was devised that measured the efficiency of a male quail’s sexual behavior.  The sexual behavior of the male quail consists of grab, mount, and cloacal contact responses.  However, a mount does not always follow a grab, nor is a mount always followed by a cloacal contact.  The “efficiency” ratio was defined as the proportion of total sexual responses that involved cloacal contact [cloacal contacts / (grabs + mounts + cloacal contacts)].  Males that quickly achieved cloacal contact with a female after grabbing her obtained higher efficiency scores.  Female behavioral receptivity was measured by calculating the time the female was immobile in the presence of a male.

The most significant result was a positive correlation between male copulatory efficiency and egg fertility. Copulatory episodes in which the male responded more efficiently tended to produce more fertile eggs. In addition, shorter latencies to make cloacal contact resulted in higher rates of fertilization. The female receptivity measure was positively correlated with egg fertility and negatively correlated with latencies to mount, grab, and make cloacal contact. Thus, receptive females permitted the male to copulate with shorter latencies and produced more fertile eggs. Group differences indicated that males trained with CS-US pairings copulated more quickly than males in the unpaired control group.

The positive correlation between male efficiency and fertility, in addition to the negative correlation between male response latencies and fertility, may be interpreted as indicating that fertility is determined by the male’s behavior. However, the correlation between the male efficiency ratio and female receptivity (which was also related to fertility) shows that a dynamic interplay of behavior between the male and female partners is required for successful fertilization of the eggs.  The present findings are significant in that they show some of the details of how male/female behavioral interactions contribute to successful reproductive outcomes.
 

Social/Personality

PORTRAYAL OF SMOKERS AND SMOKING IN TOP GROSSING FILMS

Alyssa Bartlett, Taryn Brackin, Jaime Chubb, Sandy Covatta, Liz Ferguson, Adele Hinckley, Jilda Hodges, Cheryl Liberati, Jonette Tornetta, & Catherine Chambliss

Ursinus College

Recently there has been considerable attention given to cigarette smoking in films.  In fact, a great deal of research has found that most films portray smokers in a positive light, giving them characteristics of maturity, sophistication, and of high social class.  Little attention is paid to the negative consequences of smoking.  Studies have found that audiences feel a more positive view of smoking after seeing its glamorous, exciting, and adventurous depiction in film and advertisements.  Researchers Pechmann and Shih (1999) examined smoking and smoking portrayal in films from 1990-1995.  The current study is and extension of Pechmann and Shih (1999) examining smoking portrayal in films from 1996-1999.  A list of the twenty top grossing movies from the years 1996 to 1999 was compiled.  From this list five movies from each year were randomly selected.  A group of trained raters evaluated the movies for relevant characteristics.  Demographics were recorded for first, second, and third leading characters according to age, gender, and smoking status. When asked “How is the character generally portrayed?,   raters evaluated each person on the following traits: selfish/considerate, cruel/kind, rebellious/compliant, crude/sophisticated, poor/wealthy, insecure/confident, angry/happy, unattractive/attractive, tense/relaxed, immature/mature, unintelligent/intelligent, unpopular/popular.  Nonsmokers were found to appear more considerate and less selfish.  Though not significant, there was also a trend for nonsmokers to be viewed as more kind and less cruel.  Seventy-five percent of the 1996-1999 movies sampled depicted cigarette smoking. Only 5% of the movies sampled featured three or more main characters who smoked.
 

THE EFFECTS OF COGNITIVE DISSONANCE ON ANXIETY, SPIRITUALITY, AND RELIGION

Joseph Tloczynski, & Scott Koklinski

Bloomsburg University

The present study examined the effects of cognitive dissonance on anxiety, spirituality and religiosity of psychology students at Bloomsburg University. The experiment involved the use of three separate measures for each of the variables and was conducted in a pre-post manner. Anxiety, spirituality, and religiosity were measured using Spielberger's State-Trait Anxiety Inventory, the Spirituality Orientation Scale (developed by Dr. Tloczynski), and the Francis Scale of Attitudes Toward Christianity, respectively. A modified version of Mark Twain's article "Letters From the Earth" was used to produce the dissonance. The experiment involved seven
groups of 30 students. The participants had their choice of the seven different experiment times which they could sign up for. The students received extra credit for their participation form their respective teachers. The results of the statistical analyses indicate a strong relationship between the State anxiety scores in the pre and post  measurements. The results of the independent t-test with paired values produced a P value of .001 and a mean increase in score of 2.341. These
results indicate an increase in anxiety level as a result of the dissonance producing reading. Further statistical analyses have not produced highly significant results among pairings of the other variables (e.g. P values of .0617, .049) but more analyses need to be done. Further experiments using this procedure have been planned for either the Spring or Fall of 2000.