Information processing in high- and low-risk parents: What can we learn from EEG? Social Information Processing What differentiates parents who abuse their children from parents who don t? Mandy M. Rabenhorst & Thomas R. McCanne Center for the Study of Family Violence & Sexual Assault Northern Illinois University SIP model suggests that parents who are at high risk of physically abusing their children process child-related information differently implications for behavior Social Information Processing Pre-existing existing schema set the stage for perception and interpretation of stimuli According to the model, parents who are at high risk for child physical abuse have pre-existing existing beliefs that children are hostile leads to more hostile interpretations of children s s behaviors How do we prove pre-existing existing schema? Pre-existing existing Schema? Prove it Program of theory-driven research dedicated to testing differences in information processing Borrowed methodology from cognitive and social psychologists Subliminal and supraliminal priming Lexical decision-making tasks Evaluative decision-making tasks Results generally support the model by demonstrating that high-risk for CPA parents view children as hostile hostility bias
Prove it continued Although these studies demonstrate support for the theory, it remains unproven (as theories always do ) indicating the need for continued research (definition of a program of research) Our understanding of the role of pre-existing existing schema becomes clearer and cleaner when multiple studies using multiple methodologies converge on the same pattern of results Event-related brain potentials Cognitive psychologists have been using event- related brain potentials (ERPs) to study brain activity correlates of semantic information processing ERPs occur in response to discrete events and are regarded as manifestations of information processing activities N400 Researchers have studied brain activity in response to linguistic semantic anomalies N400 is an ERP that is elicited in response to semantically incongruent information N400 = Negative-going going brain wave occurring approximately 400 milliseconds after the onset of a semantically incongruent target (final word)
The pizza was too hot to drive. N400 Applications Sentences Final word = written word Final word = picture of object Word pairs (lexical vs. semantic) Banana - Split Car - Auto Word-picture pairs Faces Within and between category violations What is N400 measuring? N400 amplitude (height of the wave) is seen as an index of the difficulty of integrating a word into a given context Context can be provided within an experiment (e.g., story) or can be pre-existing existing (e.g., child- related schema) Integrating anomalous information is relatively more difficult than integrating congruent information
Current Research Use ERP methodology to provide additional evidence that high-risk for CPA parents, relative to low-risk, have pre-existing existing schema that lead to higher levels of hostile interpretations of ambiguous child stimuli Complement previous findings using a new dependent variable N400 Occurs a few hundred milliseconds after stimulus presentation Not subject to demand characteristics Study 1 Word Pairs Child followed by positive or negative word descriptors (e.g., Nice or Hostile ) Descriptors are believed to be consistent or inconsistent with pre-existing existing schema Expect a larger N400 to be elicited in response to word-pairs that are semantically incongruent with parents pre-existing existing schema Study 2 Picture-Word Pairs Picture of an ambiguous child followed by positive or negative word descriptors (e.g., Nice or Hostile ) Ambiguity = not clearly positive or negative (as opposed to not clearly children) Expect a larger N400 to be elicited in response to picture-word pairs thought to be inconsistent with parents pre-existing existing child-related schema Picture Samples
Sounds straightforward, but N400 amplitude is influenced by: Word frequency (how frequently the word is used in every day language) Word class (noun, verb, etc.) Repetition (N400 amplitude decreases with repeated presentations of the same stimuli) Associative strength (how often a particular word was given as the associated word) First Steps (I mean, Hurdles) Programming software BioPac Measuring EEG Measuring EEG SuperLab Ground vs. Reference electrodes Matching metals Scoring/cleaning the data Removing artifacts (e.g., eye blinks, movement) Slow, laborious Tom discovered a faster, easier process
Preliminary Results: Replication Preliminary Results: Replication Can we get the same results in our lab that other researchers have gotten in their labs? Neutral Word-Word pairs Cat Dog Cat Ton Neutral Picture-Word pairs - Grass - Light Preliminary Results: Replication Replication
Preliminary Results: Risk For the child pairs, we expected High- and Low- risk parents to respond differently to child paired with positive or negative Initial investigations revealed that words and pictures might be different Omnibus ANOVA Site (9) by Stimulus (2) by Trial (2) by Risk (2) Stimulus by Trial by Risk interaction was significant (p <.025, η =.64) Stimulus by Risk separate by Trial Picture-Word Word-Word (p =.051, η =.47) (p =.014, η =.68) Questions? Contact: Dr. Mandy Rabenhorst mrabenho@niu.edu (815) 753-7093 7093