By Lauren Stowe, PhD, CCC-SLP & Gina Rotondo, MS, CCC-SLP The Speech Therapy Group

By Lauren Stowe, PhD, CCC-SLP & Gina Rotondo, MS, CCC-SLP The Speech Therapy Group

http://www.acquiredbraininjury.com/interactive brain/interactivebrain.swf

1. Hormones make the science messy 2. Difference in brain was in the hypothalamus (that regulates sex hormones & sexual behaviors) 3. Sex differences in brain not fundamental, but to be studied later 4. Sexist (Cahill, 2014)

1. Sexes metabolize drugs differently (medication Ambien, 2013) 2. Animal research proves that sex differences cannot be explained by human culture. (Cahill, 2014)

ADHD = >2:1 Dyslexia = 5:1 Autism = 4:1 (Asperger s 10:1) (Boys brains have to be changed less than girl s to become autistic, Baren et al, 2011) Stuttering = 4:1

Gray Matter (GM): Cell bodies and dendrites Purpose is to pass along sensory input CPU of the brain White Matter (WM): Axons of nerve cells and myelin (fatty sheath that covers axons). Speed of communication is determined by white matter. Cables connecting the CPU to other parts

IQ s are the same Men s GM is 6.5 times the size of women s (about 100 grams) Many women ask why men need more brain tissue in order to get the same things done. So, men have bigger brains but what do women have that s bigger?

Women s WM is 9.5 times the size of men s

Who: 949 youths (8 22 y, 428 males and 521females) Method: Diffusion Tensor Imaging (DTI) Results: Females have more left to right connectivity (corpus callosum) and cross lobe connectivity (frontal, parietal, temporal) Males have more WM within hemispheres (frontal, temporal, parietal lobes) Opposite was observed in the cerebellum Conclusions: Males process info in one spot. are suited to facilitate communication between analytic and intuitive processing models. Females process it more diffusely. Ingalhalijer et al., 2014

Steinmetz et al. 1995

Women s neuron s are 11% bigger than males in the prefrontal cortex and in the temporal cortex that is involved in language processing

Larger in women Advantage = more in touch with feelings Disadvantages = more susceptible to depression Hippocampus (memory) larger in women. Amygdala (flight or fight) larger in men Cahill, 2006; Cosgrove et al 2004

Men are more asymmetrical Kokalev et al., 2003

Method: fmri Task: Semantic pairing task (e.g., milk, beverage) Results: Bilateral activation in women Unilateral activation in men Females had less diffuse left activation and greater right posterior temporal and insula region activation than males. Conclusion: Men tend to be more left brained, while women have greater access to both sides. Clements et al., 2006; Baxter et al, 2003

Women are Better at Language : Verbal memory Phonological processing Verbal fluency Kansaku & Kitazawa, 2001; Sommer, Aleman, Bouma, & Kahn, 2004; Voyer, Voyer, & Bryden, 1995

Method: fmri study Task: Auditory Working Memory Task (QA, QABCA) Result: Females had greater signal intensity in orbital prefrontal cortices Conclusion: Men and women may use different parts of their brain to do the same job Goldstein et al, 2005

Men better at spatial reasoning (Halpern et al, 2007): Better at rotation an object Have an internal compass (I see the sun is there, we go here; left hippocampus memory center and spatial mapping) Women use landmarks (we need to find the McDonald s to get to the doctor s; right parietal and prefrontal cortices linked to visual ID and reasoning) Men can get out of a corn maze faster (German study, 2000): Men = 2 minutes 22 seconds, Women = 3 minutes 16 seconds

Men tend to act out more than women Men s motor system is activated when angry Motor system is activated when angry May be why they physically act out Women may feel sick to their stomach when upset Hypothalamus controls digestion Larger orbital frontal cortex (decision making) in proportion to the amygdala (more primitive fight or flight reaction site) May be why they physically act out Gur et al, 2012

Girls better at: attention word and face memory reasoning speed social cognition tests Boys better at: spatial processing sensorimotor speed motor speed Gur et al, 2012

Dendrites prune more quickly in girls (around 3 years old) Language develops more quickly in girls (women s superior temporal cortex is 29% bigger) Blood flow is about 15% higher in women s brains (which may be reason why women are less likely to develop cognitive decline) Nerve cells in brain more tightly compacted (may function better)